10 Formerly Secret Tunnels That Are Now Open to the Public

From hidden passageways beneath ancient cities to wartime bunkers turned tourist attractions, tunnels have long been shrouded in mystery and secrecy. Over time, many of these once-concealed corridors have been unlocked for public exploration, offering a glimpse into history that was once kept under wraps. Whether they were built for defense, transport, or escape, these 10 formerly secret tunnels now welcome curious adventurers to explore their depths and unravel the stories they hold.

Related: 10 Creepy Cool American Catacombs & Crypts You Can Visit

10 The Third Tunnel of Aggression

North Korea is one of the world’s most elusive and difficult-to-visit countries. Its tumultuous history with nearby South Korea and other major countries, such as the United States, has not made it a prime tourism destination. But that doesn’t mean it doesn’t have some attractions.

Apparently designed for a secret attack on Seoul, the Third Tunnel of Aggression is one of four tunnels in North Korea that has caused its home country some distress. When the United Nations learned of the tunnels, they accused North Korea of being in violation of their peace armistice with South Korea. North Korea claimed the tunnel was used as a coal mine and had no militaristic purposes.

Regardless of their original use, the tunnels are now shown on tours of the Demilitarized Zone (DMZ).^[1]

9 Versailles Secret Quarters

Former Queen of France Marie Antionette’s opulent home in Versailles, France, is just as grand and glitzy as you could hope. In her time, the castle would always have been alive with servants and family members, just as it’s busy with tourists today. So what’s a young woman to do when she needs a little quiet time?

For Antionette, the answer was to escape to her secret rooms within the castle. Built into the tapestried panel of the wall in her bedroom were nearly undetectable doors. These led through narrow hallways into a private suite with a library, boudoir, and lounge. It also might have played a much more critical role in history. When the French peasants made their way to Versailles in revolt during the French Revolution, it is believed Antoinette was found hiding with her children in these no-longer-secret rooms.

Though they were not originally accessible to the general public, after years of restoration, visitors can now see the elusive area.^[2]

8 The Shanghai Tunnel

Don’t believe the title. These tunnels aren’t in China but in Chinatown in Portland, Oregon. Portland is known for its weird culture and colorful history, and the story of the secret labyrinth beneath its streets fits perfectly with this image.

In the late Victorian Era, when keeping up proper appearances was essential, many lower-class dock workers weren’t so keen. They created the “Shanghai Tunnels,” which allowed them to sneak in and out of illegal brothels and saloons. The tunnels reached their peak popularity in the 1930s when the United States government banned the sale and consumption of alcohol. Multiple Portland tour groups offer different types of guided experiences, from history-based walks to spooky ghost-hunting tours.^[3]

7 KGB Cells

Former Soviet Union territories are ripe with history, especially stories about the terrifying Soviet Secret Police—also known as the KGB. Most of the KGB’s horrifying torture and interrogation techniques were more of an open secret than a true one, as they used citizens’ fear of them as a way to “keep the peace.”

But even the most imaginative villagers couldn’t have dreamed up the horrors prisoners were going through in the former KGB prison in Tallinn, Estonia. Though most of the building is now luxury apartments, in the 1950s, the building housed prison cells and torture rooms. The walls are still bricked up, allegedly to muffle the sounds of the screams coming from within.

Today, the basement tunnels operate a museum in remembrance of those who were put through unimaginable ordeals before being sent to the gulags in Siberia or killed.^[4]

6 Tunnel of Love

One of the most photographed places in Ukraine is the “Tunnel of Love” in Klevan, a town near the western border.

It’s much prettier than its carnival namesake. Rather than plastic lights and animatronics, Ukraine’s version is a gorgeous tree-lined railroad track, ideal for photo ops or a peaceful nature stroll. The canopy of trees above the tracks seems perfect. Almost too perfect.

That’s because they were planted purposefully and carefully during the Cold War to try and obscure the military hardware being transported. Ironically, the trees meant to hide the path and keep the area secret are now what makes it so famous.^[5]

5 Westminster Kingsway Tunnels

The London Eye may have the best views in the city, but the newly refurbished Westminster Kingsway Tunnels are set to be the newest tour attraction in the UK’s capital.

Below central London, a network of tunnels was built during World War II to shelter Brits from oncoming bombs. As a tribute to the survivors and victims of the war, the London Tunnels team plans to open the tunnels to the public in the near future. The underground area will feature a museum and interactive exhibits to tell the stories of those who sought shelter below the roads.

Above all, the Westminster Kingsway Tunnels will memorialize those lost to World War II while also serving as a cool new subterranean tourist attraction.^[6]

4 The Paris Catacombs

The Paris Catacombs are one of the top attractions in one of the most famous cities in the world. Morbid as they may be, these piles of bones and skeletons beneath the City of Love have attracted tourists ever since they were first opened in 1809.

Though they were never a pure secret, the eerie Paris Catacombs served as a burial site for over six million French people due to the overfilling of traditional cemeteries. Because of the delicate nature of the bodies, most of the catacombs were off-limits to the public for a long time. As the legend and beauty of the catacombs grew, more people wanted to visit, leading to the current tourist status of the bones.^[7]

3 Chicago Pedway

In a city notorious for being cold and windy, it makes sense to have secret tunnels beneath the sidewalks to shelter residents from bad weather.

Though they aren’t exactly extensive, spanning only 40 blocks throughout the downtown area, Chicago’s Pedway System offers refuge from rain and snow. The oldest parts of these underground streets date back to the 1940s and connect multiple subway train lines together. In the ’50s, the project was expanded.

Though parts of the Pedway have been off-limits at times due to private businesses restricting access, the Pedway is now entirely public. Now you have no excuse not to visit the Second City in wintertime.^[8]

2 Chu Chi Tunnels

The Viet Cong soldiers of the Vietnam War are infamous for their brutal and cunning guerrilla warfare. From booby traps to ambushes, the North Vietnamese soldiers managed to terrify and surprise Americans and South Vietnamese soldiers at nearly every turn.

One way they could keep one step ahead of their adversaries was through the Chu Chi Tunnels. Tens of thousands of miles of makeshift tunnels were dug by the Viet Cong so they could sneak around the country without detection. In addition to allowing their troops to hide out right under their enemies’ feet, the tunnels served as a “home base” for Viet Cong attacks.

The tunnels gained even more infamy after the war when smaller American soldiers were revealed to have been forced to be “tunnel rats,” crawling through tunnels to learn the routes and destroying what they could.

The formerly secret tunnels are now open for tours in two separate locations. But be sure to watch your head!^[9]

1 Alcatraz Island Tunnels

Even though it hasn’t been used as a prison since 1963, Alcatraz Island will always be known as perhaps the most infamous jail in American history. The former home to Al Capone and Machine Gun Kelly, located off the coast of San Francisco, was converted into a National Historic Landmark in 1986.

With that, visitors poured onto “The Rock” to see how criminals lived for nearly 30 years on the barren island. One of the most exciting new developments in Alcatraz’s history came in 2019 when archeologists discovered hidden tunnels under the prison yard. They weren’t dug by desperate prisoners hoping to escape. They were built during the American Civil War, sometime in the mid-1800s.

This confirmed historians’ suspicions that the island was used as a military fortress during the Civil War. While admission to the tunnels isn’t included on regular tours, the special “behind the scenes” tour does allow tourists to walk through the tunnels and even experience a few moments in the prison’s former solitary confinement.^[10]