Moscow's imposing monument to the Space Age.

Museum celebrating the achievements of the Soviet space program.

Open-air museum with a large collection of Soviet-era statues.

Monastery, army base, and infamous Soviet Gulag in the far Russian north.

Sculpture garden of religious statues made it through Soviet rule.

The California secessionist movement has its own foreign embassy, in Russia of all places.

A former top secret nuclear fallout shelter now operates like a hotel stuck in the Cold War.

A top secret Cold War bunker hidden beneath a Latvian spa facility is now open for tours.

Buried five stories underground, this Soviet bunker is packed with gas masks and Cold War paraphernalia.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

This medieval Estonian tower provides access to a series of tunnels that have been home to soldiers, punks, and fine art.

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

Abandoned Soviet base once stocked with short and medium range missiles pointed at western Europe.

This East German military command bunker was ready for World War III.

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

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

Statue of Lenin, from Cold War era Czechoslovakia, now in a neighborhood of Seattle.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Yugoslavia's biggest underground airport lies in ruins.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

Terrifying derelict military hospital once housed a recuperating Hitler.

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

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.