Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

Phil Mortillaro uses keys to bring art back to the Village.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

This former crime corner has been turned into an eclectic community center.

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

A castle built for love, and abandoned due to heartbreak.

This otherwise innocuous bodega was once the headquarters of the most feared assassin's guild in American history.

The notorious headquarters of a corrupt political machine.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

Visit the site of a subway powered by nothing more than air--and lots of it.

This former theme park in New York's Adirondack Mountains fell into ruin before being resurrected as a state-run campground

For over 80 years, Mayan ruins stood proudly in a most unlikely location.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

This enormous Hindu temple in Queens serves incredible dosas in its basement canteen.

Once America's longest-manned military fort, now an abandoned hulk.

A discreet little stairway on St. Nicholas Avenue leads to a quaint and unexpected cobblestone street of 19th century wooden rowhouses.

Hear the tales of New York's most notorious criminals.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

The last slot car racing arcade in Brooklyn is keeping the dream of speedy little autos alive.