A playground inspired by differential calculus dangles from the ceiling of the Liberty Science Center.

Vacant Beaux-Arts buildings that serve as reminders of a beach town’s glory days.

This unassuming retro burger joint was billed as “diner of the future” at the 1939 World's Fair.

World War II bunker still standing on the New Jersey beach.

Step into Monet's world at this fine-dining restaurant in the middle of a New Jersey sculpture park.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

A unique sculpture park that specializes in the huge and bizarre.

Historic Greenpoint theater, turned roller disco, now housing a chain pharmacy store.

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

The only subway station in the city that still makes use of gap fillers.

A touching tribute to the "Queen of Soul."

Home to a dizzying array of letterpress blocks with a rich history.

A remnant of the original World Trade Center complex continues to serve as a commuter gateway.

Though the case is scorched and the buttons half-melted, this hardy handheld gaming device can still run a game of Tetris.

This outdoor gallery of sculptures along the East River was once a landfill.

The highest rapid transit station in the world.

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

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.

This unusual subway stop was originally a real estate office.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

Snack on a partially gestated duck egg.

Michael Jackson got Bad and Crocodile Dundee walked on heads in this iconic Brooklyn subway station.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

In Little Caribbean, an ice-cream shop serves up regional flavors, including soursop, Irish moss, and "greatnut."