The oldest surviving synagogue in New York City is now a soaring art space.

This former Norwegian sailor's church is slowly being taken over by ramshackle robot musicians.

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

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

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

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

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

A very classy 1920s-era bar right in Grand Central Station.

New York City's smallest piece of private property.

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

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

The "Seinfeld" diner.

Ride the subways of yesteryear.

Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

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

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

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

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

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

Elevated freight railway turned wildly successful urban park.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

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