A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

An abandoned Gold Coast-era mansion once intended for the exiled ruler of Albania, who never arrived.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

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

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

Lie in a hammock where George Washington stood.

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

Once America's longest-manned military fort, now an abandoned hulk.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

A crumbling hospital from the 1850s on Roosevelt Island.