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

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

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

The world's oldest hologram gallery and the labyrinthine laser laboratory of a holography pioneer.

Tucked in a nondescript downtown Brooklyn mall is a bar containing a remarkable turn of the century anatomical wax collection last seen in 1920s Berlin.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

Sniff the Titan Arum's rotting flesh.

Read a book next to a Midtown waterfall.

Ride the subways of yesteryear.

A hands-on traveling collection of the innovative devices of yesteryear.

A New York garbage depot holds a secret collection of weird and wonderful refuse.

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

Elevated freight railway turned wildly successful urban park.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

A crumbling hospital from the 1850s on Roosevelt Island.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

This statue celebrating everyday life in Dublin has a few unsavory nicknames.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.