Museum dedicated to the terror regimes of Hungary.

Once the home of a hermetic monk, this cave now houses a small church.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

The oldest museum in Russia is home to a fascinating collection of nearly two million anthropological artifacts and anatomical curiosities.

World's largest bell sits on the grounds of the Kremlin in Moscow.

Dozens of padlock-trees along the Moscow River.

Gargantuan home of Russian science.

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

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

A huge communist-era propaganda monument and mural that offers stunning views of the Mongolian capital.

Secret North Korean passage discovered below the world's most dangerous border.

Home to more than 13,000 pieces of war memorabilia and military equipment.