The remains of a failed attempt at medieval nerdery are hidden deep in the woods of Virginia.

Abandoned 19th century homes once occupied by naval officers, soon to be demolished.

The house that took a plunge into the facade of a museum.

A Turkish ghost town abandoned in a population exchange with Greece.

Opulent downtown movie theater now houses cars as an indoor parking garage.

Detroit’s downtown castle is one of the oldest structures in the city.

A Beaux-Arts triumph set to become Ford's innovation campus

An ornate Detroit church, left empty and ravaged by time.

Abandoned concert venue legendary for its rock counterculture.

The angel of death appears to weep black tears at this grave marker.

This cemetery features modernist statues as strange as its name.

Infamous and now demolished panopticon prison built by its former inhabitants.

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

Standing in a state of "arrested decay," this ghost town allows for a detailed peek into Gold Rush life in an unusually harsh climate.

The largest underground church in Europe.

Museum dedicated to the terror regimes of Hungary.

Slaughterhouse Five opens its dank doors to fans of Kurt Vonnegut.

A 200-year-old prison that now houses a peculiar crime museum.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

Famously misunderstood wonder of the ancient world

Surreal riveted sea forts once protected the Kent shores from German attack.

A house of bones — but nobody is quite sure to whom they belong.

England's most notorious suicide spot.

The biggest and deepest Cold War bunker open to the public can be found in southeast England.