Once a major stop on the Hejaz Railway, this desert station (complete with steam locomotive) has been abandoned for decades.

In the middle of a barren desert, a massive, solitary rocky thumb juts out.

Within the Saudi Arabian desert lies a 2,000-year-old ghost town made of stone and mud.

This giant volcanic crater holds its very own field of salt.

It's believed human settlements from the Palaeolithic Age were established not far from this canyon.

A historic structure that once housed pigeons used by farmers to help fertilize farmland.

A 19th-century fortress and collection of artifacts offer a tour of Saudi history.

This centuries-old tree tells an unusual tale of vegetation and fertility in the desert.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

A unique two-level bridge designed to honor a king.

A World War II evacuation tunnel turned into a history display of Croatian state and people.

This 135-year-old weather station studied the effects of the climate on human health.

Thousands of slain Soviet soldiers are buried within the shadow of this enormous obelisk.

A cableway for car transport.

Admire dozens of life-size animals made from old scrap metal, nuts, screws, and valves.

This legendary city has been a tourist attraction for centuries.

Monasteries on rock pillars, once accessible only by frayed ropes.

An underground city of salt.

The former Nazi Germany concentration camp stands as a museum to remember this dark chapter in European history.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

A massive cave once a secret military base is now home to thousands of bats.

Underneath this Byzantinian church lies a necropolis filled with ancient tombs and the ruins of previous churches.