This amazing 15th-century mural remained hidden in plain sight for centuries.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Monks turned this mountain into a temple by digging grottoes, tunnels, and a huge pagoda-like hall.

Spend the night in this formerly abandoned traditional Scottish village.

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

An unfinished tomb carved into a giant boulder in the Arabian Desert.

More than 100 monumental tombs carved into rock are preserved at this ancient Nabataean site in the Arabian Desert.

This antique prison is a tourist attraction with a sordid past.

An ancient Scottish rock formation said to be the gravesite of a giant remains ensconced in legend and intrigue.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

This rare example of a "tidefall" is a spectacular drop from the cliffs down onto the beach.

An abandoned railroad tunnel is now filled with bioluminescent bugs.

This ruined 15th-century hermitage is steeped in myth and mystery.

This charming, medieval walled village is Spain's first "book town."

Climb atop one of the world's longest and heaviest trains for an unbelievable journey across the Sahara Desert.

This mosaic-lined medieval church was built by the world's first admiral and still holds mass in ancient Greek.

The abandoned fishing village was swept right into the sea.

One of the largest and oldest caravansaries in Persia.

The enormous earthwork sculpture honors the ponies that lived and worked in the old colliery.

A swath of France so devastated by war it is still forbidden to go there.

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

A galaxy of glowworms—larvae of a gnat—hides deep in the belly of these caves.

One of the most well-preserved temples of ancient Egypt.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.