A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

The only home that Alexander Hamilton ever owned has a history almost as troubled as his own.

Bowl in splendor, if you're lucky.

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

During the holidays, a vintage subway train whisks New Yorkers back in time.

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

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

Love, knishes, and best wishes from this legendary Lower East Side bakery.

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

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

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

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

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

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

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Ride the subways of yesteryear.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

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

A semi-scholarly approach to sex.

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

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

Beautiful antiques and obscure engineering artifacts trace the evolution of phones from rare luxuries to ubiquitous.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.