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

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Home to items never before seen by the public.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

An aptly-named street near the birthplace of the modern LGBT rights movement.

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

For 20 years, local pumpkins have met their fate on the iron fence surrounding this Cobble Hill home.

A mysterious statue of a leather jacket-clad rebel leans coolly on an odd yellow clock.

Site of the first pathological and bacteriological research facility in the United States.

This giant boulder is sandwiched between apartment complexes in upper Manhattan.

You must take the A train... to the last active cemetery in Manhattan.

This recipe is set in stone.

A one-ton statue of Steve Rogers beautifies the entry to a Brooklyn Bed, Bath & Beyond.

This was one of the first (and last) university-built and operated nuclear reactors.

An exhibition space dedicated to American outsider art created between the 18th and 21st centuries.

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

A Manhattan Episcopal church with an eerie underground crypt.

A way to take your secrets to someone else's grave.

This small, hidden cove is home to abandoned boats.

Hear the tales of New York's most notorious criminals.

Historical figures from New York City's Catholic community reside in Midtown.

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

This hidden library of physiological ephemera contains centuries worth of knowledge on the vim and viscera of the human body.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.