Once the future of underwater combat, this old sub is now open for visitors to muck around in.

Birthplace of America's first documented serial killer.

This 38-drawer structure claims the superlative title, but it isn't the world's only giant filing cabinet.

America's oldest archaeological site or a muddled case of wishful thinking.

This narrow canyon has been carved by the river over thousands of years into spectacular and curious forms.

Ruins of the elaborate house where the enigmatic costume designer threw glamorous parties for New York's theatrical elite.

Pennsylvania's own Roswell-style UFO mystery.

The New England cabin where an infamous British occultist conducted experiments in "magick".

Abandoned power station once home to a squatter community, now being developed into an arts center.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.

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

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

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

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

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

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

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

More gold than anywhere else, ever.

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

New York City's smallest piece of private property.