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

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

The oldest surviving synagogue in New York City is now a soaring art space.

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

Peek through the gates at this oasis from the city, full of Old English charm.

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

A dilapidated dock tells the story of Titanic's missed arrival.

From scholastic to sepulchral - now under reconstruction.

On the top floor of an upscale department store stands a lavish restaurant housed in a replica of a luxury French dining car.

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

A miniature rainforest is growing inside of a Midtown Manhattan office building.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

Read a book next to a Midtown waterfall.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

A hip bar decorated with walls of golden skulls.

Elevated freight railway turned wildly successful urban park.

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

Try not to get slimed in Tribeca.

Tucked in the back of this amazing antique store is an important piece of medical history.

A crumbling hospital from the 1850s on Roosevelt Island.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

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