Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Pilgrimage site for star-crossed lovers.

A diverse collection of wax, bone, papier-maché and mummified relics.

2300-year-old Roman road connecting the empire.

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

The mystic whose incorrupt corpse still attracts the faithful.

The underground sanctuary of a mysterious ancient cult.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

The world's largest wooden structure.

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Rare karst landscape eroded from a flat seabed.

Immortalized by artists, this church incorporates a medieval lighthouse into its shoreside structure.

This French ghost town from World War II has been left as a memorial to German atrocities during World War II.

The site of the first medieval crusade that pitted Christians against Christians.

Historic medieval fortified city in southwest France.

The last bastion of Roman presence north of the Alps looms over a German town.

Hiding the longest subterranean river known in the world.

This legendary giant, born from vegetables, terrorized townspeople and cheated local children in games.

According to this bar, God gave an “11th commandment” to Antwerp: Thou shalt drink beer.

An open-air sewer system that was covered piece-by-piece over 300 years.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

This ancient cave temple complex is the largest and best-preserved temple complex in Sri Lanka.