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

Now abandoned, the first public health hospital in the U.S. saw more than one million immigrants from around the world.

Site of the first pathological and bacteriological research facility in the United States.

A sculptural commentary on capitalism pokes up from the East River.

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

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

A crumbling hospital from the 1850s on Roosevelt Island.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

One of only two commuter aerial tramways in the United States.

Read a book next to a Midtown waterfall.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

Elevated freight railway turned wildly successful urban park.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

The first piece of public art dedicated to LGBT rights.

New York City's smallest piece of private property.

Those belting out show tunes might not realize this piano bar marks the site where Thomas Paine died in 1809.

This slender three-story building has also had several famous residents.

Phil Mortillaro uses keys to bring art back to the Village.

The oldest living tree in Manhattan comes shrouded in sinister legend.

The site of the deadly Triangle Shirtwaist Factory Fire.

Two large-scale sculptures of Adam and Eve greet visitors in the nude at the Time Warner Center in NYC.