NYC's legendary underground network for bovine transportation.

Walk over a 150 year old manhole.

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

A WWI fighter plane and turn-of-the-century penny candy shop are among the unexpected features of this Financial District building.

A Manhattan office building is home to the world's largest chess board.

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

A natural gas leak provides a flickering flame beneath a waterfall.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

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