This old estate is a remnant of when the Bronx was a popular summer destination for wealthy New Yorkers.

A once crucial portion of the Long Island railroad still lays abandoned, waiting to be turned into an urban park.

Queen Anne style apartment house built in 1886.

A Brooklyn exhibit all about Nancy Kerrigan and Tonya Harding in 1994.

The competition: breathe deeply as long as you can.

Underground tunnels remain beneath this abandoned mental asylum.

The last standing puppet theater on Long Island.

An unrealized dream to wirelessly electrify the entire Earth.

All that remains of a magnate's dream home is a historic gate and an abandoned public pool.

A ruined mansion hidden in the woods of the Hudson Valley, home of a tragically doomed romance.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

This abandoned ironworks was once the most important military supplier in America.

Sniff the Titan Arum's rotting flesh.

The Underground Railroad passed right through this historic Brooklyn Heights church.

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

Hidden behind a gate in Greenwich Village is a little farmhouse that once served as the writing studio of a bestselling author.

These historic buildings once housed the headquarters of one of the most infamous gangs of New York.

The most confusing clock in New York.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Mysterious 500-year-old tapestries depict a unicorn hunt.

A former insane asylum despised by Nelly Bly and Charles Dickens is now fashionable apartments.

An arcade packed with a rotating collection of unique independent video games.

Every year model trains zip through a miniature New York City that's now 150 landmarks strong.

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