Preserved portions of Athens's ancient defenses are on display in a subterranean parking garage.

After a nearly successful attempt on Hitler's life, the conspirators met their fate in the courtyard of this Berlin building.

A museum in the building where Nazi Germany signed its surrender tells the story of World War II from the Soviet perspective.

Named after a militant urban guerilla, this famous former squat is a graffiti-covered stronghold of leftist culture.

This conical hill was built as a testing ground for an engineer known as the Glider King.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

The Bulgarian royal family exclusively used this ornate, now-abandoned train station.

A collection of art from Bulgaria's time as a communist state.