Abandoned Nazi train station turned underground astroparticle laboratory.

This former charity hospital for elderly clergy houses some of Seville’s most treasured paintings.

Madrid's last horchata kiosk is a blue-and-white beacon of refreshment.

A science fiction-inspired apartment building designed by a famous Spanish architect.

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

One of the world's oldest universities houses an incredible collection of anatomical models, mummified body parts, and human bones.

A charming Spanish village sits atop this natural limestone overpass.

The little church's beautifully frescoed ceiling has earned it the nickname “the Sistine Chapel of Madrid.”

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Stunning Roman aqueduct used for 1900 years and still standing.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

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

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

A Spanish town built into the cliffs.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

Village situated on a narrow volcanic escarpment.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

This house's itty bitty size means no humans allowed.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

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

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Wonderland replication in progress by one persistent man.