Hidden well off the beaten path in Catalonia is this crumbling medieval castle that is slowly being covered in graffiti.

A road that winds through this natural cave is the only way to access the small, appropriately-named village of Cuevas.

Peek into a cave of giant, glimmering crystals.

Originally planted by the ancient Carthaginians, this sprawling palm grove is one of the largest in the world.

Medieval ruins nestled within a breathtaking swath of Spanish nature.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

This unique rock formation is quite the local celebrity, although one day it may come crashing down.

The blowhole bursts spectacularly right next to the buildings in a medieval seaside town.

Walls of stone rise up from sinkholes caused by underwater erosion.

A fiery-red region of scooped out land still largely untouched by civilization, tourists or otherwise.

See replicas of Europe's most famous cave paintings and even some of the animals that feature in the art.

A dictator's failed public works project has been reborn as two linked trails through spectacular scenery.

This enchanting green space houses a labyrinth lined with toxic plants.

One of Europe's largest groups of dolmens remains largely off the typical tourist track.

The ruins of an ancient Celtiberian town with incredible rock-cut buildings and a Roman aqueduct.

This remarkable museum sprung from one of the most important prehistoric archaeological sites in the world.

Whimsical sculptures and caves chiseled by nature over the millennia.

A spectacular walk on the flank of a gorge.

Super Robot anime statue guards a forgotten suburban development in Tarragona.

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

This panoramic lift provides a futuristic ride up San Pedro Mountain.

Abandoned 18th century weapons factory in the Aezkoa Valley.

These primitive rock paintings include a very beloved depiction of a woolly mammoth.

This Arab fortress was once the largest citadel in Western Europe.