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

A hidden "place of interment for gentlemen."

Plot your trip through the city on the sidewalk.

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

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

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

An odd, ancient window that may have once been part of a brutal prison is embedded in the side of New York's Police Plaza.

A historic 1890s architectural masterpiece with an iconic clock tower that, once open to the public, now faces an uncertain future.

More gold than anywhere else, ever.

Set sail on a small scale.

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

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

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

These etchings reveal the history of a long-gone quarantine site.