Three-story slide through the New Museum.

The phone booths of New York City have all but disappeared, but their remains were once found in this "graveyard," sadly now removed as well.

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

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

NYC's legendary underground network for bovine transportation.

Lie in a hammock where George Washington stood.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

The "Seinfeld" diner.

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

One of only two commuter aerial tramways in the United States.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

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

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

A semi-scholarly approach to sex.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Order scoops of pandan, lychee, and black sesame at this family-run institution.

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

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

Elevated freight railway turned wildly successful urban park.

New York's oldest magic store.

A crumbling hospital from the 1850s on Roosevelt Island.

Tucked in the back of this amazing antique store is an important piece of medical history.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.