This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Abandoned railway line circling the city of Paris.

This massive library holds what was once the largest book collection in the world.

Some Moscow residents once claimed the bizarre, contorted mass of metal on top of the building was used to manipulate minds.

Moscow's most popular cemetery includes the graves of numerous cosmonauts.

Former headquarters of the KGB.

Museum celebrating the achievements of the Soviet space program.

Dr. Strangelove-esque tours reveal the inside a bunker once reserved for Stalin himself.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.

A national collection of Communist-era musical posters.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.