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

The oldest surviving synagogue in New York City is now a soaring art space.

Just your average Marie Antoinette–themed speakeasy in an abandoned 19th-century subway tunnel.

Nondescript elevator doors open to reveal a stunning, surreal world.

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

The name of this famed hospital was once a byword for the horrors of medical and psychiatric care.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

A very classy 1920s-era bar right in Grand Central Station.

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

A restaurant on Staten Island showcases a different grandmother’s cooking every night.

Become a prohibition rebel.

Mysterious 500-year-old tapestries depict a unicorn hunt.

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

Sniff the Titan Arum's rotting flesh.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

A hip bar decorated with walls of golden skulls.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

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

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

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.