The remains of a 37,000-year-old prehistoric society were discovered in this mammoth cave, one of the largest in Asia.

A medieval bridge stretches over a sulfur-rich river that leads to year-round natural hot springs.

An abandoned Byzantine fortress and notorious prison.

Russian spa's bronze monument to enemas.

A Russian museum dedicated to the household staple, the samovar.

Thanks to this small string of islands World War II still hasn't officially ended between Russia and Japan.

Mostly underground in the old days Back in the USSR, today the Beatles beckon to tourists from a wall sculpture out in the open in central Russia.

Ukrainian defense contractor's center for studying "pyramid energy."

A 360 degree battlefield experience.

An abandoned town of skeletal wooden homes.

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

A city block packed with whimsical sculptures that seem to be plucked from a tiled fantasy world.

Gigantic natural towers in a Russian plateau.

Unusual, mushroom-like rock formations caused by weathering and water erosion, set to disappear, according to geologists.

Former prison camp dedicated to the victims of political repression.

A man-made island fort that has housed soldiers, scientists, and ravers.

A dormant lightning machine equal to all the power in Russia.

Nightmarish example of the unintended consequences of weapons testing.

It took over half a century but a Russian monument to a famous and tragic space pup finally stands in Moscow.

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

This ancient village and its adjoining cemetery have a beautiful history of death and remembrance.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Mysterious hillside with a continuously burning natural fire.