This dilapidated castle-like structure overlooks the Hudson River at one of its widest points and was once home to nuns.

The loneliest island in New York.

A long abandoned hospital building on the outskirts of NYC.

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.

This empty Victorian manse on Staten Island is said to be haunted but is actually a real life crime scene.

From scholastic to sepulchral - now under reconstruction.

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

This ruined fort hidden at the top of Central Park can't seem to keep from losing its historical plaques.

Holding the most bodies of any cemetery in the United States.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

Tucked in the back of this amazing antique store is an important piece of medical history.

A crumbling hospital from the 1850s on Roosevelt Island.

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

Decades after testing the polio vaccine on unwitting patients, this historic mental hospital sits in ruin.

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

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

Not even a series of devastating fires could keep this odd castle in upstate New York from bouncing back.

A railroad magnate's replica village has become home to a genetic seed bank for rare breeds of livestock.

The exact whereabouts of this surreal cabinet of curiosities are rarely the same place twice.

A coastal rock outcrop with mysterious inscriptions variously attributed to Native Americans, Portuguese, Phoenicians, Norse, and more.

This former Masonic hall has been turned into an art project that uses even more metaphysical iconography.

Unlike other abandoned asylums this empty institution welcomes visitors, just don't go in the buildings.

Funded entirely by volunteers and donors this military memorial features a tank with a comedy line on its barrel.

This unassuming Massachusetts residence was built with a trap door to hide escapees on the Underground Railroad.