A graffiti Mecca welcoming artists from around the world.

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.

Fake subway tiles were installed to cover a design that resembled the Confederate flag—it's unclear if the resemblance was intentional.

Hundreds of antique bank vault locks on display in New York City.

An unassuming secret door once led to a legendary watering hole.

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

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

The smallest island in Manhattan is a manmade landfill dominated by a Buddhist peace arch.

Everyone from Mark Twain to Teddy Roosevelt has a pipe hanging from the walls of this historic chophouse.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

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

There are owls with glowing eyes in Herald Square.

New York's oldest magic store.

This eclectic sculpture garden in Brooklyn, home to a bizarre collection of art, was once a run-down junkyard.

A celebration of capitalism in Midtown.

Manhattan and the Bronx have been playing tug-of-war over this former island neighborhood for more than a century.

New York City's only radical feminist independent bookstore.

The first "Hall of Fame" in America was designed by legendary Gilded Age architect Stanford White for what was then the NYU uptown campus.

Have a steam and some blini at this cafe in a century-old bathhouse.

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

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

Depression-era fun lives on in this Harlem museum dedicated to the sport of the street.

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

What happens here stays here – unless it affects the whole world.