A stray meteor left this picturesque hole in the Australian outback.

Prehistoric park filled with the fossils of dozens of extinct species including Australian megafauna.

A shipwreck named Desire at the shore of Batumi.

A beautiful but deteriorating monument of Soviet architecture.

Veryovkina Cave is more than 1.3 miles deep—the deepest known in the world.

The second largest in the world, this massive underground void has its own subway.

The cave holds a spectacular array of stalactites and stalagmites, including one shaped like a giant human heart.

Fast food feels like fine dining at this award-winning modern Georgian building.

The second-deepest known cave on Earth, hidden in an extremely remote mountain region.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

Small church on top of a huge rock column.

Rock-hewn monastery complex with hundreds of cave structures tucked away into the mountainside.

These Stalin-era industrial 'death traps' hang lifeless above the city

Ancient rock-hewn town that witnessed key events of Georgian history.

Hidden deep within a Filipino jungle is an incredible waterfall that plunges into a dazzling blue-green pool.

A tiny park in the middle of some big power politics.

Unfinished monument to peace between Turkey and Armenia, long divided by a dispute over genocide.

A small mountain at the crossroads of Turkey, Iraq, and Syria that some believe was the landing point of Noah's Ark.

These ruins once flourished as the capital of the Lydian kingdom, often credited with the invention of metal coinage.

A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Natural rock formation, or biblical artifact that saved Earth's wildlife two by two?

This mysterious cliffside carving of an ancient Hittite deity has baffled scholars for centuries.

This hidden gem is bathed in beautiful natural light.

Seven early Christians were sealed into a cave where legend has it they slept unharmed for centuries.