The ruined remains of the airport Claus von Stauffenberg departed in his failed attempt to kill Adolf Hitler.

Several of these strange cone-shaped bunkers can still be seen around the former Nazi headquarters.

A statue of Vladimir Illyich Lenin guards this abandoned building in the "Forbidden City."

This former steel and coal plant is now a neon-lit industrial fantasia.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

Just another terrifying garden filled with hundreds of endlessly smiling doll people.

5,000 skulls in memorial to those killed by the Khmer Rouge.

An abandoned Cambodian resort that mirrored the downfall of the country as it was happening.

A palace destined to never house a king.

A former French military respite turned jungle tourism hotspot.

Khmer Rouge's high security prison.

A battle between nature and architecture in the Cambodian jungle.

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

Croatia's towering concrete blossom grows from the site of a World War II concentration camp.

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

The only gulag ever to exist in socialist Yugoslavia.

Visit the WWII bunker where the British won the battle for the skies.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

This abandoned fighter jet launch center is now a haunting street racing course.

The gutted remains of this Estonian mansion are a monument to a tragic love.

This abandoned Olympic skiing facility still bears the scars of the Siege of Sarajevo.

A war-torn Olympic relic is being overtaken by graffiti and nature.