This mountaintop observatory is home to one of the world's largest reflective telescopes.

This taberna has been frying up crunchy salt cod since 1860.

This chest hospital with a dark, haunted past serves as a fitting set for horror films and a paradise for ghost hunters.

The cathedral of a controversial, conservative, schismatic sect that declared the Catholic Church heretical and founded its own succession of popes.

An unexpected ghost village lurks on the southeast coast of Tenerife.

A surrealist labyrinth and museum of contemporary sculptures.

A huge cathedral single-handedly constructed by one eccentric monk.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

The largest medieval water tank on the Iberian Peninsula is preserved beneath the Cáceres Museum.

A modernist church in an ancient village.

Geological storytelling.

Spain's largest bullring offers a unique glimpse at architecture and history.

Now a pile of ruins and rubble, this was a lovely mountain town as recently as 1960.

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

Beautiful tiles decorate many of the town's surfaces and stand testimony to its glorious artistic history.

Kingly French toast comes soaked in milk or red wine, then drizzled in a citrus-perfumed syrup.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

Hundreds of caves once used to store grains and animal feed.

A network of hundreds of interconnected wineries in caves hides under the town center.

This influential Renaissance-era library was once the haunt of kings and monks.

The atmospheric ruins of a historic church can be found on a hill above the city of Oviedo.

Down this yellow brick road, visitors are treated to toadstool houses and massive mushroom sculptures.

A magnificent, long-abandoned castle built in the wake of the reconquest of Spain.

This imposing modern citadel started out as a home renovation project.