An abandoned asylum where patients have been forgotten but their possessions remain.

This innocent-looking townhome is actually a subway exit.

Protecting the future of some of the rarest and most misunderstood mammals of North America.

Visit the monolithic tomb of America's most famous general.

This once luxurious Catskills resort is now a haunting ruin.

Cryptic messages embedded in the New York City sidewalk.

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

Nondescript elevator doors open to reveal a stunning, surreal world.

Manhattan's lighthouse, erected at the insistence of the unsinkable Molly Brown.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

A hidden "place of interment for gentlemen."

This abandoned subway station can still be seen on regular commuter trips.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Reclaimed by nature, the ruins of Doodletown, New York are remnants of a town consumed by a state park.

Lie in a hammock where George Washington stood.

What was once a trend-setting, phrase-coining icon of architectural splendor is now a rotting, forgotten hulk.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

In the middle of downtown Brooklyn lies a 165 year old secret hidden right below the surface (closed to the public indefinitely).

The oldest house in Manhattan is now a museum that remembers the home's sordid history of scandals, vice-presidents, and ghosts.

A dark, dank room in subterranean Manhattan was the site of a ghastly murder.

A popular European tradition makes its way to the states on one of America's most famous bridges.

Deep under Manhattan is the largest construction project in city history. So far, the project has taken the lives of 23 workers, or "a man a mile."

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."