In a pedestrian tunnel on North Carolina State’s campus resides an expressive and artistic free-for-all.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

An arcade packed with a rotating collection of unique independent video games.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

An unassuming secret door once led to a legendary watering hole.

A tunnel once abandoned now thrives with graffiti art as an off-limits makeshift gallery.

A hands-on traveling collection of the innovative devices of yesteryear.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

A room in New York City that contains 250 cubic yards of dirt worth a million dollars.

One of only two commuter aerial tramways in the United States.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Try not to get slimed in Tribeca.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

A crumbling hospital from the 1850s on Roosevelt Island.

A beautiful and abandoned New York subway station from 1904, complete with chandelier.

A common entry point to the Griffith Observatory trail holds its own wonders.

World's largest collection of serial killer artwork and other macabre exhibits.

Ingenious bakery opens up the first Cupcake ATM at their flagship location in Beverly Hills.

Resting place of Hollywood's immortals is also site of summer film screenings.