10 STRANGE CITIES HIDDEN UNDER OTHER CITIES

Cities being built on top of ruins of ancient cities. Subterranean caverns running beneath today's cities. Underground fortresses and secret facilities being built. Many cities world wide have entire cities located beneath them, some centuries old and others relatively new.

Here are just a few of those places.

1) Edinburgh Vaults

Located in the nineteen arches of Edinburgh's iconic South Bridge, the Edinburgh Vaults were used to house tradesmen as well as the city's less desirable residents. When it was constructed in 1785, the bridge was intended to expand the city, and also serve as a custom-built shopping district. Along those ends, buildings located on the bridge's arches were given underground storage areas. Unfortunately, the storage vaults began to flood and were evacuated by their rightful owners. Shortly afterward, Edinburgh's downtrodden moved into them. The damp, dark rooms were a hotbed for crime, with serial killers Burk and Hare frequenting them for victims. [They were notorious body snatchers who became serial killers when there weren't enough 'legally' executed criminals to supply their need for bodies to sell to medical schools] Tons of rubble was dumped into the Vaults in the mid-1800s to close them down for good, but an access tunnel was discovered in the 1980s, leading to some fascinating discoveries. The underground city now has conducted tours.

2) Napoli Sotteranea

If you were to pick a European city that would be least likely to host an underground secret, Naples might be on your list. The flooded canals of Campania's capitol actually lay atop a bed of volcanic rock known as tuff, which is easy to mine and work. Over the centuries, a massive system of tunnels and caverns have been carved out of this material. The ancient Greeks used them as reservoirs, but there are also many fascinating ruins down below, including theaters and early Christian worship sites. During World War II, the tunnels were used for air raid shelters.

3) La Ville Souterraine

Most of the subterranean cities here have fallen into disuse and disrepair, but the massive complex beneath the streets of Montreal is one of the city's main commercial hubs. La Ville Souterraine was constructed after the Metro subway system opened in 1966, and covers over 20 miles of space under the city. Entry points are constructed around residential or commercial businesses at the surface, and the network contains underground stores, restaurants, nightclubs, and a library. During the bitterly cold winter, the majority of the city's commerce happens below the streets.

4) Burlington Bunker

The English country town of Cortsham, Wilshire, doesn't seem like it would be hiding any dark secrets, but guess again. Buried 100 feet below the quaint cobblestone streets lies a massive, sprawling subterranean city built in case a nuclear attack targeted London. The Burlington Bunker consists of 35 acres of construction and over 60 miles of roads. It was designed to support a maximum population of 4,000 people and boasted a number of amenities, including a television studio, cafeterias, and even a pub. Many of the walls are decorated with colorful murals. The existence of Burlington Bunker was classified until 2004, when it was decommissioned. It was never used, not even for test exercises.

5) Old Sacramento

In 1862, massive flooding swept through California's capitol, submerging both homes and businesses. The Legislature was relocated to San Francisco and the people who were left behind tried to figure out how to prevent a disaster like that from happening again. The solution was to raise all of the city's streets by ten feet, building new construction vaulted above the remains of the old. The abandoned spaces were used for storage and other purposes, and there is still a good amount of old Sacramento architecture left untouched beneath the surface, illuminated by squares of rose quartz set into the sidewalk as makeshift skylights.

6) Beijing Underground

The Cold War saw the threat of global nuclear annihilation loom heavy over our heads, so it's not surprising that many world leaders saw fit to head underground for safety. Perhaps the most ambitious project was Mao Zedong's underground city, which covers a staggering 33 miles of catacombs beneath the capital. China began construction in the 1970s when tensions with the Soviet Union were high, and the sprawling complex eventually came to contain medical clinics, schools, theaters, and even a roller rink. Food would come from a subterranean mushroom farm. It was opened to tourists in 2000, but closed in 2008. Some parts of the complex are now being used as illegal apartments.

7) Subtropolis

Having an office with a window is a nice perk, but for the workers of Subtropolis, that is not an option. This massive cave system carved out of the bluffs above the Mississippi River hosts 50 companies and thousands of employees working in a giant limestone mine. Subtropolis makes up a complex larger than downtown St. Louis's business district, and hosts the U.S. Postal Service's collectible stamp stockpile, a number of data centers, and an artisanal cheese aging facility. Even 5K and 10K races are held in this underground complex.

8) Paris Catacombs

Over 200 miles of tunnels, caves and catacombs stretch beneath the streets of Paris, France, and are used for a variety of fascinating purposes. Originally hollowed out for limestone when the city was being built, the Paris catacombs have been used for corpse disposal, mushroom farming, and hideouts for the French resistance during World War II. They were closed to the public in 1955, but a whole subculture has arisen around the underground city. Explorers have renovated tunnels, built living areas and even hosted art exhibitions in the Paris catacombs. The structural integrity of the remaining quarry walls are monitored by a team of French officials as they have been known to cave in and take whole neighborhoods on the surface with them.

9) Las Vegas Tunnels

The glittering streets of Las Vegas are a playground for people from all over the world with its tempting gambling, nightlife, and food. But beneath the streets, a subterranean city houses the unlucky people chewed up and spit out by Sin City. In the 1990s, with the tourism boom putting lots of tax money into the city, Vegas built a system of drainage tunnels to protect the city from flash floods. The 200 miles of tunnels have now become home to about a thousand people, who create living spaces in the cramped, scorpion-filled spaces and hope that the rain doesn't wash away everything they own.

10) Underground Seattle

One of the most famous underground cities in America was created as a result of a major disaster. In 1889, a cabinetmaker working in Seattle's Pioneer Square area tipped over a glue pot, which caught fire and started a massive blaze that destroyed 31 blocks of the city. Instead of just rebuilding, the City Council decided to raise all of the streets one to two stories higher than the old height. This created a cavernous area of walled-in sidewalks, with glass skylights in the street's above, that people used to get from business to business, as well as the remnants of buildings damaged by the fire. Seattle condemned the Underground in 1907 following a bubonic plague scare, but it was opened for tours in 1965. I've taken this tour [actually, took it on two different occasions]. Fascinating place.