15 Hidden Underground Cities in the World You Never Knew Existed

Hidden beneath our feet lie some of humanity’s most astonishing treasures – underground cities.  The largest of these subterranean wonders spans an incredible 32 kilometers of tunnels across 41 city blocks in Montreal, Quebec.  The locals know it as La Ville Souterraine.

Life bustles quietly underground while people go about their daily routines on the surface.  Montreal’s underground network connects over 80% of downtown office spaces and draws nearly half a million visitors each day.  The ancient underground city of Derinkuyu in Turkey stretches back to the 8th century BC.  Its network of 18 tunnel levels could shelter up to 20,000 people.  The massive underground civilization of Dixia Cheng in Beijing spreads across 85 square kilometers.  The complex was built to protect one million people for up to four months during nuclear threats.

The UNESCO World Heritage Wieliczka Salt Mine in Poland and SubTropolis in Missouri, the world’s largest underground business complex, showcase human ingenuity at its best.  This piece uncovers 15 extraordinary ancient underground cities that have stayed hidden from public view despite their rich history and architectural brilliance.

Derinkuyu, Turkey

Derinkuyu, one of the world’s most remarkable ancient underground cities, lies deep in Turkey’s Cappadocia region.  This massive subterranean maze stretches 85 meters below ground with 18 distinct levels of tunnels.  The city stands as a testament to human ingenuity and survival instinct.

History of Derinkuyu

Historians still debate Derinkuyu’s origins.  Archeological findings point to the Phrygians starting construction in the 8th-7th century BC.  Hittite artifacts found in upper levels suggest even earlier beginnings.  Several civilizations expanded this underground network over time, including the Persians and early Christians during the Byzantine era.

The city reached its peak during the Byzantine period.  Up to 20,000 people sought refuge here from Arab Muslim raids between 780-1180 AD.  The underground sanctuary protected inhabitants during Mongol invasions in the 14th century.  The Christian inhabitants left in 1923 after the Greece–Turkey population exchange.  The tunnels remained hidden until people found them again in 1963.

Unique Features of Derinkuyu

Derinkuyu’s architectural brilliance shows ancient engineering at its finest:

• Defense mechanisms – Massive rolling stone doors, weighing up to half a ton, sealed each level from inside.  Small holes let defenders spear invaders
• Self-sufficiency systems – The complex had over 15,000 ventilation shafts, water wells 55 meters deep and spaces for livestock, wine production and food storage
• Specialized spaces – The city featured churches with altars and benches, schools with barrel-vaulted ceilings, storage rooms and a missionary school on the second floor

The city connected to other underground communities through tunnels up to 9 kilometers long, creating a vast network of subterranean settlements.

Accessibility and Tourism at Derinkuyu

Derinkuyu opened its doors to visitors in 1969 and earned UNESCO World Heritage status in 1985.  Tourists can now explore eight of the eighteen levels, about half of the underground city.

The Nevşehir-Nigde highway leads to Derinkuyu, with regular busses running from major Turkish cities.  Entry costs between 100-300 Turkish lira (about £6.50).  The temperature stays cool inside, so visitors should wear comfortable clothes and sturdy shoes while exploring the narrow passages.

Montreal RESO, Canada

_{Image Source: The Montreal Visitors Guide}

Montreal’s RESO stands apart from ancient underground refuges as a modern marvel of urban planning.  The French call it La Ville Souterraine (The Underground City), and this massive network started in 1962 by connecting Place Ville Marie, the Queen Elizabeth Hotel and the Central Train Station.

History of Montreal RESO

The harsh climate and downtown congestion in Montreal sparked RESO’s creation.  The network grew rapidly after the metro system opened in 1966.  Urban planners designed this network to help people avoid extreme weather and reduce surface traffic.  The underground passages grew significantly through the decades and became the world’s largest habitable underground network.  The network got its name “RESO” in 2004, which cleverly plays on the French word réseau, meaning “network”.

Unique Features of Montreal RESO

RESO’s impressive numbers make it unique among global underground developments:

• Spans 32 kilometers (20 miles) of tunnels covering more than 41 city blocks (approximately 12 km²)
• Connects to 80% of downtown office space and 35% of commercial space
• Houses over 2,000 shops, 200 restaurants, 40 banks and 40 cinemas
• Links 8 metro stations, 2 train stations and multiple bus terminals

The network keeps comfortable temperatures throughout the year, giving shelter from Montreal’s bitter winters and humid summers.  RESO offers more than shopping with its cultural venues, museums, concert halls and universities.  Art lovers can explore extensive public installations, including a piece of the Berlin Wall and beautiful stained-glass displays.

Accessibility and tourism at Montreal RESO

RESO runs alongside Montreal’s metro system hours from 5:30 am to 1:00 am.  The network serves about 500,000 people daily through its 190 exterior access points.

Montreal’s transit authority helps tourists navigate this maze-like system with detailed signage and maps.  Visitors love exploring the four-story Eaton Center with its 100+ stores, Les Cours Mont-Royal (a converted 1920s hotel) and the Atrium Le 1000 skating rink that operates year-round.

Naours, France

_{Image Source: La Cité Souterraine de Naours}

The subterranean city of Naours stands as a testament to human ingenuity in northern France’s Picardy region.  Ancient communities created this secret underground haven to protect themselves from invaders.  The Romans first carved out this limestone quarry in the 2nd century AD, which grew into one of northern France’s most extensive tunnel networks.

History of Naours

The story of Naours began as a simple Roman quarry but evolved as locals adapted the space to store goods and shelter from invasions.  These caverns became crucial for survival as conflicts kept ravaging the region.  The underground refuge reached its peak during the 17th century’s devastating Thirty Years’ War, providing shelter to 3,000 residents.

Father Danicourt found this forgotten marvel in 1887 after European conflicts had settled down.  Naours soon became a popular tourist spot.  The site played a fascinating role during World War I as thousands of Allied soldiers stationed nearby visited it.  They left behind over 3,000 pieces of graffiti—the largest collection of WWI inscriptions on the Western Front.  The Nazis later used this underground complex as their headquarters during World War II.

Unique Features of Naours

This remarkable network runs 22-33 meters (72-108 feet) deep with tunnels that stretch 1-2 miles westward beneath modern Naours.  The complex shows impressive organization with:

• 28 galleries and 300 hand-carved chambers
• Three chapels, multiple town squares, stables, bakeries with working ovens, and wells
• Smart chimney designs routed through buildings above ground to hide underground activities

The city’s inhabitants could live independently underground.  They raised livestock, baked bread, and held religious services while armies marched across northern France.

Accessibility and Tourism at Naours

Visitors can explore this extraordinary underground civilization just 18km north of Amiens.  The underground temperature stays steady at 9-9.5°C, so warm clothes are essential.  The underground tour comes with many steps and rough terrain, making it challenging for wheelchair users or people with mobility issues.

The estate offers more than just the underground city.  Guests can enjoy a 10-hectare wooded park, adventure facilities, windmills, farm animals and activities for children.  The site welcomes visitors Tuesday through Sunday from 10:00-17:30 on weekdays and 10:00-18:30 on weekends, staying closed on Mondays.  A complete visit takes you through the Underground City tour, Museum of Ancient Trades and a new interpretation center called “The Traveling Soldiers”.

Dixia Cheng, Beijing, China

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Beijing’s busy streets hide an extraordinary Cold War relic – Dixia Cheng, known as the “Underground Great Wall.” This vast network of tunnels, built between 1969 and 1979, stands as one of the world’s most ambitious underground cities.  The Soviet-Chinese relations had deteriorated, and the city needed a shelter that could protect Beijing’s entire population during nuclear war.

History of Dixia Cheng

The year 1969 marked the beginning of Dixia Cheng’s construction amid rising tensions with the Soviet Union.  The border conflict over Zhenbao Island in the Heilongjiang River sparked immediate action.  Chairman Mao Zedong rallied his citizens with a clear message: “dig deep tunnels, store food and prepare for war”.  The project brought together around 300,000 civilian labourers who worked with simple tools like shovels and bamboo baskets.  These residents worked for a decade without modern excavation equipment.  For large-scale underground construction projects today, professional digger hire services provide essential machinery that significantly improves efficiency and safety compared to manual excavation methods, making complex underground developments more feasible and cost-effective.

Unique Features of Dixia Cheng

This underground wonder covers more than 85 square kilometers, with tunnels running 8-18 meters deep.  The network features:

• Three distinct zones linked by roughly 30 kilometers of tunnels for cars, busses and pedestrians
• Direct access to major landmarks like Tiananmen Square, the Forbidden City, Beijing Train Station and the Temple of Heaven
• Detailed facilities including restaurants, clinics, schools, theaters, factories, hotels and a mushroom cultivation farm

The engineers gave Dixia Cheng robust defense systems.  These included 2,300 ventilation shafts with poison gas seals, water-proof hatches and thick concrete main gates that could withstand nuclear fallout.

Accessibility and Tourism at Dixia Cheng

Dixia Cheng welcomed tourists in 2000 but has remained closed for renovation since February 2008.  Visitors once entered through small shop fronts in Qianmen or near the Temple of Heaven Park.  The entrance fee jumped from ten Chinese cents in 1981 to twenty Renminbi later.

Tourists could explore about one kilometer of the thirty-kilometer complex.  They saw chambers with their original function labels, signposts pointing to major landmarks and fading slogans like “Accumulate Grain”.  The tour showcased a working silk factory and included a souvenir shop.  While tourists can’t visit anymore, parts of the complex now serve as affordable housing for migrant workers.  These underground residents have earned the nickname “Rat Tribe”.

Wieliczka Salt Mine, Poland

_{Image Source: UNESCO World Heritage Center}

The Wieliczka Salt Mine in Poland stands out as one of Europe’s most amazing underground cities.  This underground wonder near Kraków shows proof of human craftsmanship carved completely from salt.  The mine ranks among the world’s oldest salt mining operations and stayed active from the 13th century until 1996.

History of Wieliczka Salt Mine

Salt production’s earliest records go back to 1044 when Casimir I gave special rights to local salt collectors.  People mainly got salt from surface brine before the 13th century.  The springs got weaker over time, so they built wells that led them to find rock salt.  King Casimir III the Great helped the mine grow by a lot in the 14th century and built a hospital nearby in 1363.  The mine became one of the world’s most productive by 1871.  The Habsburg rule took over after Poland’s 1772 partition and the mine grew into Galicia’s largest industrial operation.  The mine stopped commercial operations in 1996 because salt prices dropped and flooding became a big problem.

Unique Features of Wieliczka Salt Mine

The mine’s most amazing features include:

• A huge network of 245 km with over 2,000 chambers on nine levels, going 64-327 meters deep
• Four underground chapels, where St. Kinga’s Chapel shines brightest—workers carved everything from salt, even the chandeliers
• Many artistic salt sculptures and monuments, including one of astronomer Nicolaus Copernicus, who came to visit in 1493
• Underground saline lakes, halls and stables

The miners built this underground sanctuary over hundreds of years.  They worked and carved religious figures during their free time.

Accessibility and Tourism at Wieliczka Salt Mine

About 1.2 million people visit this underground world each year.  Visitors can choose between two routes.  The Tourist Route stretches 3.5 km and goes 135m deep, showing key areas like St. Kinga’s Chapel and underground lakes.  The Museum Route runs 1.5 km and features historical exhibits with horse mills and salt crystals.  The temperature stays steady at 17-18°C underground.  Guests walk down 800 steps but get to take an elevator back up.  The mine’s special air quality helps people with breathing problems.

UNESCO made Wieliczka a World Heritage site in 1978, making it one of the world’s most important cultural treasures.

Orvieto, Italy

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The medieval town of Orvieto sits on volcanic tuff in central Italy.  A maze of tunnels, caves, wells, and chambers lies hidden beneath its streets.  This underground network ranks among the world’s most amazing ancient subterranean cities.  People have expanded this hidden underground network for approximately 2,500 years, which created an extraordinary civilization below the surface.

History of Orvieto

The Etruscans built Orvieto, then called Velzna, around the 9th century BC on a volcanic plateau they could defend.  These ancient builders faced a tough challenge – their water source lay outside the city walls.  They dug wells and tunnels into the soft volcanic rock to solve this problem.  This network became the foundation of an extensive underground system.  Roman forces captured Velzna in 264 BC after a two-year siege.  The underground spaces grew larger during medieval times.  The 13th century saw major expansions as Orvieto became a powerful city-state.

Unique Features of Orvieto

The underground complex has several amazing features:

• Extensive network – The city sits above more than 1,200 connected tunnels, caves and chambers that form an underground maze
• Multilevel construction – Several levels run deep underground, featuring unique pyramidal chambers that get wider at the bottom
• Functional spaces – These caves served many purposes over time.  People used them to make olive oil with complete mills, raise pigeons in dovecotes, create pottery and collect water

St. Patrick’s Well (Pozzo di San Patrizio) stands out as an architectural masterpiece.  This 175-foot-deep well has 496 steps and helped people get water during sieges.

Accessibility and Tourism at Orvieto

Tourists can explore this underground world through guided tours near Piazza del Duomo.  The “Orvieto Underground” tour takes about an hour.  Visitors see several key chambers, including a medieval olive mill and ancient dovecotes.  Adult tickets cost 8 euros, while reduced tickets are 6 euros.  Kids under 5 get in free.  The temperature stays cool year-round, so visitors should bring warm clothes.

Archeologists haven’t explored much of the underground network yet and keep finding new areas.  Each visit takes you through thousands of years of history.  You’ll see how different generations used these underground spaces to meet their needs.

More on the hidden pyramid of Egypt.

Coober Pedy, Australia

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Coober Pedy stands as a remarkable underground wonder in Australia’s stark Outback.  The residents here don’t build houses – they dig into hillsides.  This unique settlement shows how people adapt to extreme environments rather than defending against enemies.

History of Coober Pedy

The story of Coober Pedy started in 1915 when a teenage boy found opal gemstones in this barren part of South Australia.  The discovery drew miners to the area, many of them soldiers returning from World War I who wanted to make their fortune.  The name has interesting origins – it likely comes from Aboriginal Kokatha words “kupa piti,” which means “white man in a hole”.

The opal industry struggled during the Great Depression as prices dropped.  Things turned around in 1946 after Aboriginal woman Tottie Bryant found new opal fields.  European migrants arrived in the late 1960s and brought machines that revolutionized opal mining into a multi-million dollar industry.  Today, this amazing place produces about 70% of the world’s opals.

Unique Features of Coober Pedy

The underground city’s “dugouts” – homes carved into hillsides – make it special.  These underground dwellings have real advantages:

• The temperature stays at 23°C (73°F) all year, while outside it often hits 40°C (104°F) in summer
• Insects stay away – locals say “when you get to the door flies jump off your back, they don’t want to come into the dark and the cold”
• People save money on energy bills since above-ground residents pay “an absolute fortune for heating and cooling”

The underground world covers more than just homes.  You’ll find churches, hotels, shops, museums and even bookstores.  These excavated homes come with modern comforts like electricity, water and internet.

Accessibility and Tourism at Coober Pedy

Tourists can reach this fascinating place by small plane, coach tours, car, or the Ghan railway line. Popular spots include the Umoona Opal Mine & Museum that shows mining history, Faye’s Underground Home (hand-dug between 1962-1972), and the Serbian Orthodox Church with its detailed wall carvings.

The Desert Cave Hotel lets guests sleep underground for about USD 150 per night. Visitors can try “noodling” (searching for opal pieces), join local mining tours, or drive to Kanku-Breakaways Conservation Park to see stunning desert views. Movie buffs might spot locations from Mad Max Beyond Thunderdome (1985), showing how this underground marvel has earned its place in global culture.

Guanajuato Tunnels, Mexico

_{Image Source: Travel By Mexico}

Beneath the vibrant facades of Guanajuato, Mexico’s colonial treasure, lies an amazing secret – a complex network of underground tunnels that now serves as the city’s main transportation system.  These tunnels stand apart from typical underground cities.  The city planners turned what was once flood control infrastructure into an innovative traffic solution.

History of Guanajuato Tunnels

Mining operations in the 16th century created these tunnels to redirect the Rio Guanajuato away from downtown to stop flooding. “La Galereña,” the longest tunnel, came to life in the early 19th century.  Miners used their expertise and dynamite to control river flow during rainy seasons.  The city grew on steep hillsides through the mid-1500s, which led to narrow streets that couldn’t handle cars.

The 1960s brought a challenge as cars became popular.  The city launched a bold engineering project to strengthen and transform these tunnels into underground roads.  Cars first rolled through these tunnels in 1961.  The network keeps growing as new tunnels join the system.

Unique Features of Guanajuato Tunnels

The underground network stands out with these distinct features:

• Directional traffic flow – Eastbound vehicles use underground routes while westbound traffic stays above ground
• Multiple levels – The network has layered crossroads and complex underground intersections
• Pedestrian access – Each tunnel has sidewalks and some even feature underground bus stops

Most tunnels stay deep underground in darkness filled with exhaust.  Some sections surface to showcase buildings, bridges and architectural arches.  The network now has 27 inbound and outbound arteries.  These tunnels span different eras – from the 1800s to additions made just 15 years ago.

Accessibility and Tourism at Guanajuato Tunnels

Tourists can explore this underground maze, but navigation can be tricky.  GPS systems often mix up upper and lower passages.  They sometimes show “intersections” that actually sit dozens of feet apart vertically.  Poor air quality from exhaust fumes can affect pedestrians.

The “Guanajuato City + Tunnels + Mines Private Tour” lets visitors drive through subterranean streets inside mountains.  Independent travelers might prefer shorter tunnels that connect key spots, like the route from Embajadoras Park to La Comer supermarket.

The historic center’s underground section draws many tourists.  It features brick arches, support columns and traces of its past life as a riverbed.

SubTropolis, USA

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Kansas City’s SubTropolis lies hidden beneath the Missouri River bluffs as North America’s largest underground business hub.  People know it as “The World’s Largest Underground Business Complex,” a modern take on underground cities built for business rather than shelter.

History of SubTropolis

Kansas City Chiefs owner Lamar Hunt’s vision brought SubTropolis to life.  He bought land in the 1960s to build an amusement park called Worlds of Fun.  Hunt saw something special in the mining operation beneath his land and started leasing industrial space in the excavated limestone.  Ford, Pillsbury, and Russell Stover became the first businesses to move in back in 1964.  The story began in the 1940s when miners dug into a 270-million-year-old limestone deposit called Bethany Falls.  Their work ended up creating 55 million square feet of space, with 14 million square feet ready for industrial use.

Unique Features of SubTropolis

This underground business world stands out with some amazing features:

• Covers 1,260 acres (5.1 km²) and goes down 160 feet below ground
• Stays between 65-70°F all year without needing heat
• Has 8.2 miles of lit-up paved roads and 2.1 miles of railroad track
• Gives space to more than 55 companies and about 2,000 workers

The limestone structure shows incredible strength—6 times stronger than concrete at 18,000-24,000 pounds per square inch.  Businesses save big here too. Rent costs 30-50% less than above-ground spaces. One company saves $35,000 every month just on utilities.

Accessibility and tourism at SubTropolis

Security stays tight at SubTropolis with officers watching things around the clock.  A simple grid system makes getting around easy with 40-foot wide roads running north-south and east-west.  While business comes first here, SubTropolis welcomes runners from everywhere for the yearly Groundhog Run that helps Ability KC.  Runners love that they can wear “shorts and a T-shirt in January”.  Visitors can drive right into this underground wonder.  The staff suggests stopping at the office just inside to check out a model and see Lamar Hunt’s statue.

Sapporo Underground, Japan

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Sapporo, Japan stands out as one of the world’s snowiest major cities.  The city built an innovative underground network that works as both practical infrastructure and a lively public space.  This underground pedestrian area shields people from harsh weather and creates a space where people connect beneath the city’s busy streets.

History of Sapporo Underground

The underground pedestrian path ChiKaHo became part of Sapporo’s cityscape in 2011.  The city’s Center Revitalization Project brought this development to life.  Sapporo’s challenging climate, with yearly snowfall reaching 4.79 meters, made this project essential.  We built ChiKaHo to be the city’s main pedestrian route.  The walkway runs right under Sapporo’s main street, Sapporo Ekimae-dori, linking key urban spots in a straight line.

Unique Features of Sapporo Underground

ChiKaHo stretches 521 meters from Sapporo Station (point J1) to Odori (point J4).  The network breaks down into three parts:

• 143 meters between points J1 and J2
• 162 meters between points J2 and J3
• 217 meters between points J3 and J4

The underground network reaches beyond ChiKaHo and connects to other below-ground malls like Pole Town and Aurora Town.  People can find comfortable rest areas with tables and chairs, free Wi-Fi and open squares that host different events.  Point J2’s wooden columns and locally crafted furniture have become popular design highlights.

Accessibility and Tourism at Sapporo Underground

People can walk between major spots in just 10 minutes through ChiKaHo.  The space links directly to Odori Park, a year-round event hub.  Visitors discover Hokkaido tourism displays, local product shops, and art exhibitions throughout the network.  Aurora Town branches east from Odori Station toward Sapporo TV Tower.  This detailed system lets everyone move around one of the world’s snowiest cities while staying warm and dry.  The network has become a smart solution for both locals and tourists who want to explore the city without dealing with snow.

Napoli Sotterranea, Italy

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Naples hides an amazing underground world beneath its busy streets.  Napoli Sotterranea’s network of tunnels, tanks, and cavities reaches 40 meters below ground.  This mirror image of the city above runs under the entire old town and tells a 2,400-year story through its maze-like passages.

History of Napoli Sotterranea

The Greeks started digging under Naples in the third century BC.  They needed tuff stone to build their “Neapolis”.  The Romans took this network further during the Augustan period by building an impressive aqueduct system.  Springs near Serino, 70 kilometers from Naples, fed this system.  These tunnels served many purposes over time, but water supply remained their main use until 1885.  A cholera outbreak that year forced people to abandon the old system.

The underground spaces became air raid shelters during World War II.  Records from 1939 show 436 refuges at 616 different addresses.  People dumped rubble and garbage in many tunnels after the war.  This buried the historical treasure for years.  The underground world stayed forgotten until the late 1960s.  A group of passionate professionals then created the first association to study Naples’ underground.

Unique Features of Napoli Sotterranea

The underground network stands out with several remarkable features:

• Greek-Roman aqueduct parts still show hydraulic plaster on their walls
• War relics from WWII remain in perfect condition, including furniture and graffiti
• Underground garden shows how vegetables can grow in this unusual setting

Some cisterns still hold water two meters deep.  Visitors can also explore the ancient Teatro di Nerone (Nero’s Theater), which gives a glimpse into Roman cultural life.

Accessibility and Tourism at Napoli Sotterranea

Tours start from Piazza San Gaetano in the historic center.  Visitors walk down 136 steps to reach 40 meters below today’s street level.  A typical tour takes about 90 minutes.  You’ll see ancient cisterns, aqueducts and wartime shelters.  One special part involves walking through a narrow, 40-meter passage lit only by candles.  This part stays optional for anyone who doesn’t like tight spaces.

Groups can’t exceed 30 people and everyone must wear masks.  The temperature stays cool underground all year.  You should bring a light jacket even in summer.

Taipei City Mall, Taiwan

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Taipei City Mall stands as Taiwan’s largest underground commercial corridor.  This 825-meter subterranean space delivers a unique shopping experience that ranks among the world’s most modern underground cities.  The bustling marketplace houses nearly 200 shops and connects multiple transportation hubs throughout Taiwan’s capital.

History of Taipei City Mall

The story of Taipei City Mall began in October 1992 when Taipei City Government demolished Chunghwa Market (中華商場), a premier shopping destination from the 1960s-70s.  Chunghwa Market’s path loosely traced Taipei’s former west wall, which Japanese forces tore down in 1900.  The area faced decades of decline and traffic problems until officials decided to revolutionize it.  The mall opened its doors on March 29, 2000 and provided new space to 810 original market vendors.  The final phase completed on March 15, 2004, as the Station Front Metro Mall reopened to welcome the remaining 254 vendors.

Unique Features of Taipei City Mall

The underground complex showcases several notable features:

• Spans 825 meters with 28 entry points—14 on each northern and southern side
• Features 187 shops divided into four zones: clothing, miscellaneous goods, electronics and food
• Dedicates special areas to video games, anime merchandise, figurines and gashapon (capsule toys)

People often call this complex the “Akihabara of Taipei”, drawing parallels to Tokyo’s famous electronics and anime district.  The mall’s first underground floor houses retail spaces, while the second level serves as parking.

Accessibility and Tourism at Taipei City Mall

The mall links major transport hubs including Taiwan Railway Administration, Taiwan High Speed Rail, Taipei Metro, Beimen Station and Taoyuan Metro.  This integration makes it easy to reach for tourists and locals alike.  Year-round operation provides shelter whatever the weather.  Visitors can enter through doors marked with the letter Y or use Taipei Main Station’s vast underground network that connects to other shopping areas below ground.

Helsinki Underground, Finland

A remarkable network of tunnels stretches 200 miles beneath Helsinki.  The Finnish capital’s underground system makes it one of the world’s most carefully designed subterranean cities.  This maze of tunnels serves both daily needs and national security purposes.

History of Helsinki Underground

The city started digging these tunnels through bedrock in the 1960s.  The initial purpose was basic – power lines and sewers needed space.  City planners soon saw bigger possibilities and expanded the network to include retail shops, cultural venues and sports facilities.  Finland’s location next to Russia, with their shared 833-mile border, partly influenced this expansion.  Helsinki became the world’s only city with a complete underground master plan by 2011.  The Temppeliaukio Church, built in 1969, stands as an early success story that draws 850,000 visitors each year.  The Amos Rex art museum opened underground in 2018 because the building above it couldn’t be expanded due to protection status.

Unique Features of Helsinki Underground

Helsinki’s underground world stands out for several reasons:

• The space doubles as everyday infrastructure and emergency shelter, complete with filtration systems, food/water supplies and cots
• More than 400 premises spread across 200+ kilometers of tunnels
• You’ll find museums, churches, go-kart tracks, hockey rinks, and swimming pools
• The Common Utility Tunnel eliminates the need for street-level utility work

Buildings over a certain size must include bunkers by law.  Helsinki has built over 5,000 bomb shelters – enough room for everyone in the city.

Accessibility and Tourism at Helsinki Underground

Temppeliaukio’s stunning design and excellent acoustics have made it one of Finland’s biggest tourist draws.  The Amos Rex museum adds 23,500 square feet of exhibition space that quickly became popular with long lines and sold-out shows.  The network helps residents too.  They can park their cars underground in central Helsinki and take elevators straight to department stores without bundling up for cold weather.  The city has set aside 55 unnamed rock resource areas, each about 30 hectares, for future growth.

Shanghai Underground, China

_{Image Source: Portland, Oregon}

Shanghai leads China’s modern underground space development with trailblazing solutions that stand apart from traditional subterranean networks.  The city’s underground areas reached an impressive 126 million square meters by 2021.  This achievement makes Shanghai one of China’s greatest urban planning success stories.

History of Shanghai Underground

Shanghai’s underground space usage began in the early twentieth century.  Two underground warehouses larger than 1000 m² appeared in Huangpu District in 1919.  The city had modest beginnings with less than 0.14 million m² of underground facilities before 1949.  These included shopping malls, reservoirs and basements.  The underground landscape grew from about 2 million m² in the early 1990s to more than 68 million m² today.  The city published guidelines to help large cities create low-carbon “resilient cities” that could withstand disasters.  A major announcement about underground space usage came during the Shanghai Summit on Global Urban Underground Space Development and Utilization.

Unique Features of Shanghai Underground

Shanghai’s underground development showcases several unique elements:

• Depth progression – The development started with shallow underground spaces and now reaches depths of 36 meters below surface at the Shanghai North Bund Xinggang International Center
• Specialized facilities – The city boasts remarkable attractions like the Bund Sightseeing Tunnel, a 646.7-meter passage under the Huangpu River with multimedia effects and 360-degree views
• Engineering innovations – The city excels in shield tunnel construction methods, pipe-jacking technology and underwater pipe-sinking technology

The InterContinental Shanghai Wonderland stands as the city’s boldest underground project.  This luxury hotel sits within an abandoned quarry, with 16 of its 18 floors below ground.

Accessibility and Tourism at Shanghai Underground

The Bund Sightseeing Tunnel shines as Shanghai’s top underground tourist spot.  Driverless carriages connect the Bund to Lujiazui Finance and Trade Zone in just 3-5 minutes.  Passengers enjoy amazing visual and sound effects that make them feel like explorers.  Summer hours run from 9:30-22:30 (April-November), while winter hours are 9:30-21:30.  A one-way ticket costs CNY 50 and round trips cost CNY 70.  Visitors can reach the tunnel through Metro Line 2, busses 33, 55, and 65 or City Sightseeing Bus lines.

Petra, Jordan

Petra sits majestically in southwestern Jordan’s red sandstone cliffs.  This rock-carved capital city shows an amazing blend of underground chambers and surface architecture.  The city thrived as a busy crossroads between Arabia, Egypt and Syria-Phoenicia for almost 500 years.

History of Petra

The 6th century BC old city of Petra (first named Raqmu) was the Nabataean Kingdom’s capital.  The bustling metropolis had about 30,000 residents during its peak between 400 BC and 106 AD.  The Nabataeans grew wealthy as skilled traders who controlled the profitable incense routes and collected a 25% tax on imports.

King Aretas IV’s reign marked the city’s greatest development.  Roman forces took control of Petra around 106 AD and made it part of their growing empire.  The city saw Christianity spread during the 4th century, as shown by several large churches.  Major earthquakes in 363 AD and later centuries led to Petra’s decline, and people left the city around the 7th century.

Unique Features of Petra

Petra has several amazing features:

• Rock-cut monuments with more than 3,000 structures including tombs, living spaces and grand dining rooms
• Ingenious water management system with channels, tunnels, diversion dams, cisterns and reservoirs that helped people live in this dry region
• Architectural fusion that combines Nabataean traditions with Hellenistic elements, best seen in The Treasury (Khazneh) with its 38.77-meter-high facade

Archeologists found 12 burials beneath The Treasury in 2024, the first surviving tombs from Petra.  New excavations across the archeological park continue to teach us about this ancient civilization.

Accessibility and Tourism at Petra

Petra Archeological Park covers 264,000 square meters in Wadi Musa.  Visitors walk through the stunning Siq, a mile-long slot canyon with 24-story-high rock walls on both sides.  The park welcomes visitors from 6:00-18:00 in summer and 6:00-16:00 in winter.

Tourists should spend at least two days to see the major sites properly.  These include the Treasury, Street of Facades, Royal Tombs and the Monastery which needs climbing 1,000 steps.  Petra’s nighttime experience runs on Monday, Wednesday and Thursday at 20:30, when hundreds of candle lanterns light up the path to the Treasury.

UNESCO named Petra a World Heritage site in 1985 and it became one of the Seven New Wonders of the World in 2007.

Comparison Table

Appreciate Underground Cities in the World

These amazing underground cities stretch across continents and span thousands of years.  They show how humans can adapt and create state-of-the-art solutions.  Ancient peoples carved shelters into soft volcanic rock.  Modern city planners built complex networks under busy cities.  Through time, these underground spaces have served many purposes.  They’ve been safe havens from invaders, shelter from harsh weather and even nuclear bunkers during the Cold War.

The architectural and engineering feats in these underground spaces are impressive from any era.  The 8th century BC Derinkuyu’s complex air systems, Wieliczka’s salt sculptures carved by hand and Helsinki’s complete underground plan all show incredible problem-solving abilities.  The size of these projects is mind-boggling.  Montreal has 32 kilometers of tunnels, Shanghai developed 126 million square meters underground and Dixia Cheng can protect a million people in emergencies.

The sort of thing I love is how these underground wonders keep changing over centuries.  Guanajuato’s medieval tunnels now serve as main transport routes.  Ancient quarries under Orvieto house olive presses and dovecotes.  So many of these once-hidden spaces now attract millions of visitors each year.  Their mysterious passages have become museums, shopping centers and cultural spots.

Of course, these underground cities are nowhere near all the underground spaces in the world.  Without doubt, many more remain hidden or unexplored, waiting under our feet for future generations to find.  These hidden worlds ended up showing a basic truth about humans – when faced with environmental challenges, security threats or just limited space, people throughout history have looked downward.  They’ve built extraordinary civilizations beneath the ground we walk on every day.

FAQs

Q1. Are there any hidden underground cities that still exist today?
Yes, there are several hidden underground cities that still exist today.  Examples include Derinkuyu in Turkey, which extends 85 meters underground with 18 levels, and Naours in France, with 28 galleries and 300 chambers carved into limestone.  While many ancient underground cities are now tourist attractions, some modern underground developments like Montreal’s RESO continue to serve as active, hidden infrastructure beneath major cities.

Q2. What is the largest underground city in the world?
The largest underground city in the world is Montreal’s RESO, also known as the “Underground City.” It spans 32 kilometers of tunnels across 41 city blocks, connecting to 80% of downtown office space.  The network houses over 2,000 shops, 200 restaurants and welcomes approximately 500,000 people daily.

Q3. Why were underground cities built?
Underground cities were built for various reasons throughout history.  Ancient underground cities like Derinkuyu were primarily constructed for defense and shelter from invaders.  Others, like Wieliczka Salt Mine, began as industrial sites.  Modern underground developments such as SubTropolis in the USA serve commercial and storage purposes, while cities like Helsinki’s underground network are designed for both everyday use and emergency shelter.

Q4. Can you visit underground cities as a tourist?
Yes, many underground cities are open to tourists.  Popular sites include Derinkuyu in Turkey, Wieliczka Salt Mine in Poland and Napoli Sotterranea in Italy.  These attractions often offer guided tours that allow visitors to explore ancient chambers, tunnels and unique features.  However, some underground developments, like parts of Beijing’s Dixia Cheng, are currently closed to the public.

Q5. How do people live in underground cities?
Living in underground cities varies depending on the location and purpose of the underground space.  In modern examples like Coober Pedy, Australia, residents have fully-equipped homes carved into hillsides, complete with modern amenities.  These underground dwellings offer protection from extreme surface temperatures.  In other cases, like Montreal’s RESO, the underground city is not for permanent residence but serves as an extension of the aboveground urban environment, providing shopping, dining and transportation options.