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

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

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

Elevated freight railway turned wildly successful urban park.

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

A crumbling hospital from the 1850s on Roosevelt Island.

Holding the most bodies of any cemetery in the United States.

A graffiti Mecca welcoming artists from around the world.

Ride the subways of yesteryear.

Final resting place of two dozen New York City harbor ships.

A church of bones, decorated with 40,000 human skeletons.

Looming communist pillar with a Czech twist.

Macabre astrological automaton clock dating to the late 1400s.

First a horse rendering plant, then a 19th century landfill, this beach is full of glass from thousands upon thousands of broken bottles.