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

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

More gold than anywhere else, ever.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

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

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.

A semi-scholarly approach to sex.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Elevated freight railway turned wildly successful urban park.

Try not to get slimed in Tribeca.

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

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

A crumbling hospital from the 1850s on Roosevelt Island.

A terrific purveyor of natural history objects and curios.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.