A huge musical instrument played by the ocean.

The walkable ruins of an 19th century hotel, destroyed in a horse cremation gone wrong.

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

This small, hidden cove is home to abandoned boats.

The most unloved grain elevator in Brooklyn was a “Magnificent Mistake.”

A mysterious, abandoned building rotting on the Brooklyn waterfront.

A massive forgotten storehouse from 1913 on the Brooklyn Waterfront has a spectacular view of Brooklyn.

A charming "tea atelier" hidden away in Greenpoint, Brooklyn.

An abandoned saucer-shaped monument in the Bulgarian mountains.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.

This concrete ship has had four careers - World War I tanker, floating amusement park, fishing pier, and artificial reef.

An abandoned boat that's been stranded mysteriously for decades.

The headquarters of a secretive order is also a beautifully-designed park.

The loneliest island in New York.

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

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

A long abandoned hospital building on the outskirts of NYC.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

A poignant memorial to a young boy whose death spurred a dramatic increase in organ donations in Italy—dubbed the "Nicholas Effect."

An abandoned Cold War missile radar site.