1. The Paris
Over six million people rest deep under the heart of one of the most luxurious cities in the world, Paris, France. The Paris Catacombs are known as underground ossuaries, a series of underground tunnels that initially connected the city’s stone quarries.
The Paris Catacombs were created for one gristly reason; to cope with overflow from the city’s cemeteries. Once completed, nightly shipments of the dead were sent straight into the catacombs, filling in the grim underground cemetery that you can tour today.
In 1874, the catacombs opened to the public and today are one of Paris’ top attractions. Visit the depths if you dare, but remember that they are crammed with remnants of unfortunate souls that never quite did have a proper burial.
2. Pilsen Historical Underground
The Czech Republic’s Pilsen Historical Underground is over 12 miles of passages, wells, cellars, and hidden rooms tucked under the city of Pilsen.
The underground attraction has a unique and practical function; it was a storage space that doubled as an escape route if the city was ever attacked.
The Czechs also found that it was the best spot to store their most prized possession; beer! The cool underground environment kept their beer fresh and also allowed them to squirrel away food for lean times.
Since the Pilsen Historical Underground is full of nooks and crannies, some people believe that there’s actually treasure buried in the walls. However, anyone who goes searching for it can expect to deal with the above-ground police.
Today, you can take a tour of the underground, specifically the ice cellar, water tower, and old beer cellars.
3. The San Francisco
Tunnels San Francisco’s sewer system stretches for 1000 miles, and if you’re not careful, you might just get stuck down there forever. Comprised of sewer mains with only a few maintenance hole covers for escape, the San Francisco Tunnels are one hell of an adventure; if you don’t mind getting a little bit wet and risking losing your way and your life in the deep underground.
Although adventurers can explore the world beneath California’s prized city, you should never venture down there if it’s been raining. Additionally, hydrogen sulphide has been noted in some of the tunnels, a nasty substance that can knock you out or even kill you if you’re not careful.
Still, those who make it through San Francisco’s maze are in for a fantastic surprise. The tunnels spill out straight into the Pacific Ocean, and the view is spectacular.
4. RESO Montreal
RESO is a fascinating underground network of restaurants, movie theaters, apartments, libraries, shops, and hotels. Built in 1962, this attraction is far newer than most of the candidates on our list, but it’s equally stunning.
The idea behind RESO was to allow people to commute to work and play without having to deal with Montreal’s notoriously rough winters.
Since the swinging 60s, this project has expanded even more, and today there are more than 20 miles of tunnels and 120 access points from the upper world.
You can book a guided tour or wander through RESO on your own. Since the entire subterranean city is fully protected from the elements, you can travel here at any time of the year.
5. The Shanghai Tunnels
These tunnels are actually located in Portland, Oregon, but if you found yourself in them during the turn of the last century, Shanghai is precisely where you’d end up. Portland was a booming port city with one problem; there weren’t enough men for all of the ships.
Portlanders developed an ingenious and terrifying system of enlisting new “recruits.” Their tunnels were already dens of filth, acting as prostitute houses, opium dens, and even makeshift prisons. During Portland’s heyday, legend has it that unfortunate men who had had too much to drink would find themselves in the tunnels, sold on ships, and wake up with raging hangovers halfway to Shanghai.
The process was even called “getting Shanghai’d” and is enough to make you think twice about ordering that second beer.
6. New York’s Abandoned Subway System
New York’s abandoned subway system is a graffitied labyrinth of history, culture, and even a secret door to the Big Apple’s premier nightlife. The subway system in New York City is 115 years old, and many of the tunnels are layered right on top of each other.
With new routes being mapped all of the time, it’s easy to understand how certain areas could fall out of fashion and into disrepair. Since New York City is the town that’s constantly reinventing itself, these tunnels don’t stay vacant for long.
Sure, the subways are gone, but the tunnels have a new life of their own with graffiti, underground parties, art galleries, and even VIP events. If you want to get a taste of real New York City, it’s best to head underground.
7. Mary King’s Close
The city of Edinburgh, Scotland, was ground zero for the Black Plague, and Mary King’s Close was where most unfortunate plague victims were kept. Edinburgh is a city famous for its grim lore, history, and tragedy, but Mary King’s Close really takes the haggis.
Mary King’s Close dips under the bustling Royal Mile, and you can step right back into a time when plague victims were holed away underground, including one unfortunate little girl. According to local legend, plague victims were locked in the close itself, forcibly quarantined, so they didn’t spread the Black Plague.
Those who lived, and died, in the close usually succumbed to that gruesome fate, so Mary King’s Close is full of ghost stories. Countless visitors have seen apparitions and felt hot or cold sensations while walking the narrow streets of the close.
The close’s most famous ghostly resident is named Annie. Apparently, Annie was abandoned as a child and forced to live in the close. Visitors bring gifts for Annie, usually toys or dolls, so she doesn’t feel as lonely.
8. Dixia Cheng Bejing’s
Dixia Cheng is an expansive underground city built in the 70s. Its entire purpose was to shield China’s citizens from bombings, nuclear attacks, war, or other catastrophes, and it’s full of 100 enigmatic secret entrances, hospitals, schools, and places to sleep. Locals know it as the “Underground Great Wall,” and although Dixia Cheng was never used to barricade the population from harm, it’s still totally impressive.
Beijing opened up Dixia Cheng in 2000, and you can take a tour of a small slice of the famous underground mega-bunker. Most of Dixia Cheng is off-limits, so it maintains its air of secrecy, but you can get a little taste of what China had in store for its thousands of residents.
9. Edinburgh’s Vaults
Edinburgh’s Vaults were built to house undesirables and are famous for their despair, murder, and exploitation. They are also home to some of Edinburgh’s most disturbing ghosts. Mr. Boots is the vaults’ resident lurker.
He’s an eerie, malicious presence, and many visitors have heard the sounds of his heavy footfalls while they’re exploring the vaults. He’s the most common ghost that those brave enough to traverse the vaults encounter, but there are more.
Aristocratic gentlemen, children, prostitutes, and the lost souls of working-class people have all been seen, felt or heard in the vaults. There’s a compelling reason why this part of Edinburgh draws so many ghost stories; it was a truly dismal place to live.
These vaults are comprised of winding chambers and tunnels, all underneath the South Bridge of the city. They opened in 1788 when Edinburgh’s population was swelling, and their primary and most optimistic purpose was to house tradespeople.
Quickly, people began to take advantage of the vaults’ secrecy, and they became a haven for anything underhanded or illegal. The vaults became a sprawling flophouse for the poorest residents of the city, and they were vulnerable to everything from exploitation to serial killers.
Famous serial killers William Burke and William Hare reportedly scouted for victims in the vaults, where they would slaughter at will and then sell the corpses to local medical schools. Nobody knew, or asked, where Burke and Hare got their fresh bodies from, and it makes sense why.
The people who lived in the vaults were considered totally unwanted, and with the strong anti-immigrant sentiment in Edinburgh at the time, the mostly Irish population was seen as entirely dispensable.
With all of that sorrow going down below, travel the vaults at your own risk!
10. M42 Underneath
New York City’s Grand Central Terminal is a piece of wartime history shrouded in mystery and only acknowledged in 1980.
Welcome to M42, a secret power station that was vital during the Second World War. M42 protected the New York Central Railroad, a known German target, and kept tabs on German intelligence as well. Although M42 itself has been declassified, nobody actually knows where its specific location is. We only know that it’s somewhere buried deep underground in mid-town Manhattan.
Grand Central Terminal has tons of basements, each with a different purpose, but M42 is different. It’s carved right into the subterranean bedrock of the earth.
Some speculate that M42 is 110 feet below the ground, but it’s impossible to know for sure. M42 is only accessible by one elevator and a single staircase.
Neither of them are marked with any signage whatsoever. M42’s location isn’t listed on a single blueprint, and everything that we know about the mysterious nerve-center is either deciphered from classified documents or hearsay.
Ultimately, that’s what makes M42 one of the most confounding and fascinating secrets on the planet. Thanks for watching! Would you rather get Shanghai’d in Portland’s infamous tunnels of decadence, or spend a night in Edinburgh’s Vaults? Let us know in the comments section below.