Show Thumbnails
Show Captions

In a world of GPS and Google Earth, cities can still hold secrets. As author Moses Gates reveals in his book, Hidden Cities: Travels to the Secret Corners of the World's Great Metropolises (Penguin), even population centers have unexplored corners. "They are places you know of but you thought of as inaccessible." Although Gates' urban explorations aren't always legal, there are plenty of places visitors can explore without trespassing, including vacant prisons and abandoned subway stations. He shares some favorite hidden spots with Larry Bleiberg for USA TODAY.

Shanghai Tunnels

Portland, Ore.

Some interesting parts of Portland are literally beneath the surface. Tunnels in Chinatown were once used for deliveries, but also played a role in corruption, violence, gambling and prostitution. "It's an interesting combination of archaeology, urbanism and tourism," Gates says. 503-774-4522;

Eastern State Penitentiary


Just a few miles from the Liberty Bell, Philadelphia preserves a monument to incarceration. The now-abandoned 19th-century Eastern State Penitentiary was built to put every prisoner in solitary confinement. Residents included Al Capone and bank robber Slick Willie Sutton. It's now open for tours. "It's definitely creepy. Lots of peeling paint, lots of rusty bars, lots of weeds in the courtyard," Gates says. 215-236-3300;

Wabasha Street Caves

St. Paul, Minn.

Parts of Minnesota's capital city are built on sandstone, into which mines were dug in the 1800s. During Prohibition some served as speakeasies. Today, they're the site of weekly swing dances and tours relating its notorious gangster past. "A lot of these caves were for storing and growing mushrooms. Now you can visit officially," Gates says. 651-224-1191;

Rapid Transit subway tunnel


Although Cincinnati completed a small subway in 1928, it was never put to use. Once a year, the Cincinnati Museum Center offers a chance to visit the mass-transit system that never transported anyone. The tour, which sells out far in advance. "It's an abandoned subway system, what could not be cool about that?" Moses says. 800-733-2077;

Plymouth Church Underground Railroad stop


Just like an actual transit system, the Underground Railroad followed by escaped slaves had stations. One of the most important stops was beneath the Congregational Christian Church in Brooklyn Heights, where famed abolitionist Henry Ward Beecher held the pulpit. The tunnel-like basement can be visited on tours. "It really brings home the human aspect of what these places meant," Gates says. 718-624-4743;

Abandoned zoo

Los Angeles

Although the tigers and elephants are long gone, you can still find rusty zoo cages near a picnic area in the L.A.'s Griffith Park. The attraction was abandoned in the 1960s, leaving an urban relic for hikers to discover. "You can go and walk around the whole thing," Gates says. 323-644-2050;

Missile Site Park

Weld, Colo.

As home to an intercontinental missile, this area outside Fort Collins used to be top secret. Now it can be seen on regular tours. The military deactivated it in 1965 and for decades the county used it for storage . Visitors see an underground service building and the actual underground launch site where the Atlas E missile was stored and ready to fire. 970-397-8541;



As Paris grew in the 1700s, it ran out of burial places. The solution? More than 200 square miles of quarries under the city, which ultimately served as the final resting place for millions of Parisians. Centuries later, visitors see the remains in an atmospheric underground ossuary. "You go in and see all the bones. It's very creepy," Moses says.

Basilica Cistern

Istanbul, Turkey

Who says infrastructure has to be boring? The richly decorated Roman-era water cistern was constructed during the sixth century to store water brought in by aqueduct. Now found beneath modern Istanbul, it surprises visitors with its graceful design. "In addition to being functional it really is beautiful. It has columns with ancient Roman stonework," Moses says.

Harbour Bridge Climb


Moses, who has illegally climbed bridges around New York, says there's quite a thrill in seeing a city from such an unusual vantage point. "Bridges are an amazing experience," he says. It's possible to get a similar rush without breaking the law in Australia, where visitors scale ladders, stairs and catwalks as they're led to the top of the iconic bridge span.

MORE: 10 great places for museum mysteries