This secret collection of the strange and occult was rediscovered in a forgotten room of an old house.

Iron Age runes and ruins hide in plain sight along this Portuguese beach.

An abandoned tuberculosis hospital said to be haunted by the patients who died within its walls.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

A subterranean house of worship carved right out of the bedrock.

The design of this beautifully crafted building was inspired by Norwegian glaciers.

France's most famous cemetery, with some of its most curious tombs.

An old department store turned Nazi prison turned artist commune.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

One of downtown Berlin's last reminders of its Communist past.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

A spectacular Bulgarian cave resembling a devil's head with a waterfall rushing down its throat.

Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.

This sublime architectural marvel is a rare example of an expressionist church.

A mountain pass in Bulgaria's Balkan Mountains was the site of four historic battles.

A magnificent, glittering building tucked into a tiny Bulgarian mountain town.

An abandoned saucer-shaped monument in the Bulgarian mountains.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

These warring psychedelic crags commemorate an unsuccessful military operation.

This huge metal monument is slowly being stripped to its concrete skeleton.