A Canadian POW for German soldiers during WWII where prisoners hatched an elaborate escape plan.

A school teacher's massive and terrifying self-built castle.

Canada's subterranean Cold War museum has doubled as a movie set.

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

An abandoned subway tunnel that could have reinvigorated Staten Island still lies somewhere beneath this Brooklyn park.

The abandoned husk of a mental institution that failed to save a Jazz Age icon still sits nearly unchanged.

The remains of a failed subway in upstate New York is now an underground graffiti bunker.

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

This abandoned subway station can still be seen on regular commuter trips.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.

A former connection to City Island, it has been abandoned since the 1930s.

This railroad tunnel was once the longest in Massachusetts.

This former theme park in New York's Adirondack Mountains fell into ruin before being resurrected as a state-run campground

A deteriorating 1990s Girl Scout camp in a beautiful lush park on Lake Ontario.

This old cement mine has been used as everything from a mushroom farm to a recording studio.

An abandoned asylum where patients have been forgotten but their possessions remain.

An abandoned asylum once on the cutting edge of lobotomies may be reborn as a Christian college.

An abandoned Victorian-era amusement park is rusting away amidst luxury houses.

This Detroit ruin was once a gothic bastion of its community, but now it stands as a haunting ruin.

This abandoned school has had many lives since the early 1900s, and all of them doomed.

An iconic steel and chrome diner from the 1940s left empty for nearly 20 years is in danger of being demolished.

The remains of a century-old mansion that met a fiery demise years after it was deserted.

A recently abandoned psych ward at the end of Sanatorium Road.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.