The dairy farm in upstate New York where nearly half a million people gathered for three days of peace and music in 1969.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

The former estate of the Guggenheims, part of the opulent Gold Coast that inspired the Great Gatsby.

A mysterious air force base built to resemble a Long Island fishing village.

This Queens hospital has stood abandoned for almost 20 years after its patients were secretly relocated in the dead of night.

The abandoned grounds and derelict greenhouses of this once-magnificent Edwardian estate are now a nature preserve open for exploration.

An eccentric playboy's astounding natural history collection.

A formerly abandoned mental institute, now back in business.

This outpost of America's most popular fast-food restaurant is housed inside a palatial mansion.

An abandoned Gold Coast-era mansion once intended for the exiled ruler of Albania, who never arrived.

A Victorian cemetery in the heart of Brooklyn remains a popular mecca of morbid curiosity.

This mouldering abandoned mental hospital was once a center for progressive healing.

An oasis of calm amid the chaos of the boardwalk, the museum traces the heritage of this beloved beachside amusement park.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

The first and only carousel with a lineup entirely of insects.

One of the most enjoyable bits of history at Coney Island and “the most romantic ride in the world.”

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

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

A long abandoned hospital building on the outskirts of NYC.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Read between the lines of the subway map to find the hidden abandoned Civil War fort.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

Ride the subways of yesteryear.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.