Avoid gangster interaction while window-shopping.

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

Comprehensive gaming collection of over 30,000 electronic games and consoles.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

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

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

The site of a tragic massacre that spawned a multimedia franchise.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles

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

Three-story slide through the New Museum.

A huge resale shop for the cast-offs of the film & television industry.

This innocent-looking townhome is actually a subway exit.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

Plot your trip through the city on the sidewalk.

This semi-hidden Manhattan restaurant is based out of a loading dock.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

The oldest family-run luncheonette in New York, last renovated in 1948, still serves food and drinks the old-fashioned way.

Behind a bodega is a small museum of relics and ephemera showcasing the history of New York.

An accidentally hidden library containing the ephemeral history of New York.

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

Tucked away amidst some of the most famous addresses in the world is New York's only fraction of a street.

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