Geological storytelling.

This abandoned mansion has a window for every day of the year, and is a temple for ghost hunters.

A living art gallery painted on a canvas of Monterey pine trees.

A contemporary art installation housed within a Gothic cathedral.

The odd cement nubs littering this Spanish square are actually the entrances to a series of buried silos.

A site outside Pedraza, Spain where a plaque tells a tale of seven-legged creatures that were said to have once lived in the area—in the fictional world of Kcymaerxthaere.

The oldest Roman lighthouse still in use.

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.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

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

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

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

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

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

This ancient rock painting is the oldest evidence of humans’ love affair with honey.

In this coastal town, the time-honored tradition of reenacting the struggle between the Christians and Moors includes the arrival of the Moorish fleet.

This "flat geyser" bubbles up out of the ground periodically like a disappearing river.

Whether they are bulls or pigs, these ancient animal sculptures are fascinating relics.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

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

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This 19th-century fountain's namesake animal isn't what you think it is.

A strange anthropomorphic stele with a mysterious inscription that has never been deciphered.