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

Volcanic rocks ground down into sand make this Spanish beach as black as night.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

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

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

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

Village situated on a narrow volcanic escarpment.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

The morbid items in this small and hidden museum are not for the weak stomached.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

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

Turntable anonymously received orphans, alms, and groceries.

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

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

A beautiful but toxic fountain of mercury.

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

This enigmatic building features numerous architectural styles.

There are eight natural springs around town, each with a slightly different taste.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

This portion of a lovely Belize beach is infested with (harmless) sharks and rays.

This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

One of the most accessible undersea plane wrecks in the world.