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

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.

A bit of retro transportation flair preserved in the world's largest department store.

Need to book a room at the Hotel Pennsylvania? Just dial up 6-5000.

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

Church in Manhattan holds the bloody sock of Padre Pio, among with many other unusual relics.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

The one-time epicenter of American songwriting is now a little remembered Manhattan commercial block.

Nikola Tesla's former home contains an homage hidden from plain sight.

The former hotel where Tesla invented the radio.

Cryptic messages embedded in the New York City sidewalk.

A good place to research the Freemasons, esoterica, occultism, and hermeticism.

Stunningly detailed mosaics in a New York subway station bring life to the Weimaraners of artist William Wegman's work—and to thousands of commutes.

The first museum in the United States dedicated entirely to posters.

Twenty-three trees, each paired with a basalt stone, line a street in Chelsea, continuing an urban project started by German Fluxus artist Joseph Beuys.

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

Manhattan's deadly West Side railroad, which killed hundreds of New Yorkers, is remembered by this simple plaque.

The home of one of America's most beloved fictional characters has become a real world landmark.

This New York holdover was built to provide housing for shopgirls and still does not allow men above the lobby.

NYC's legendary underground network for bovine transportation.

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

The beautiful tunnel that ran from the lobby to Penn Station is still hidden underneath 34th Street.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.