Rummage through this sunken ship, but leave your scuba gear at home.

There must be a pun in this haystack somewhere...

A staggering collection of photographs depicting medical, social, and historical change.

A Manhattan Episcopal church with an eerie underground crypt.

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

Hidden in one of New York's oldest subway stations is the final remnant of the site of the bizarre Shakespeare Riots.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

A collection of fanzines, recordings, and documents detailing the rise and influence of the feminist punk movement.

Cryptic messages embedded in the New York City sidewalk.

A hidden "place of interment for gentlemen."

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

A living archive of urban activism and space reclaimed.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

The walls are decorated with whimsical murals painted by the creator of the Madeline franchise.

During the holidays, a vintage subway train whisks New Yorkers back in time.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

For over 30 years the walls of this Harlem schoolyard have been a gallery of street art by "Kings and better."

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

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

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

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

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

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

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