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

A long-abandoned provincial prison left to crumble in the frigid air of Ontario.

This forgotten building was one of the few Philadelphia-area breweries to survive Prohibition.

World's first "penitentiary," meant to be humane, drove men insane.

An abandoned tuberculosis hospital moulders on into an uncertain future.

Buffalo's abandoned concrete grain elevators are getting a second life.

A forsaken wonder in the middle of the East Side neighborhood.

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

This abandoned seaside fortress is now simply an imposing ruin being taken back by nature.

This demolished goliath of American industry once loomed over the depressed town it once made thrive.

A long abandoned hospital building on the outskirts of NYC.

From scholastic to sepulchral - now under reconstruction.

A formerly abandoned mental institute, now back in business.

The abandoned grounds and derelict greenhouses of this once-magnificent Edwardian estate are now a nature preserve open for exploration.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

These World War I shooting range tunnels are now haunted halls of underground graffiti accessed through the roots of a tree.

Forgotten under the construction of a new urban roadway is a small, abandoned part of town.

This abandoned radar station from the Cold War era now only broadcasts a seriously ominous air of isolation.

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

The once abandoned ruins of a Victorian beachside amusement park are now back in working order.

Ruins of a historic medical facility sits eerily by the water.

This enormous abandoned factory is now a makeshift graffiti gallery.

Reforestation in action is the main attraction in this abandoned quarry.

An abandoned 146-acre summer resort slowly being reclaimed by nature.