Peek into a cave of giant, glimmering crystals.

This Michelin-starred restaurant sheds light on a rare period of cultural and culinary tolerance in Cordoba’s past.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

A medieval village holds a very modern hotel.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This century-old ruined temple was reborn as "The Church of Skate."

Two large posteriors in one giant statue.

One of Europe's oldest yew trees has lived more than 2,000 years.

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

This tiny river island switches sovereignty every six months as part of a rare, centuries-old agreement.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

A landscape decorated with enormous skull sculptures.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

A five-square-mile slice of Spain on the Mediterranean coast of North Africa.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

An enchanting landscape of ancient sandstone structures eroded into otherworldly shapes.

A small Portuguese cottage formed between boulders in the countryside.

A 12th century church completely covered in shells.

A Spanish artist builds his own castle.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.