This enormous censer uses a pulley system installed over 400 years ago.

Archaeological site of Iberian people ruins.

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

You can soak in three relaxing pools filled daily by the tide.

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

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

A breathtaking and biodiverse wilderness in the mountain setting of Ernest Hemingway's "For Whom the Bell Tolls."

The ruins of a bombed medieval village memorialize the destruction of the Spanish Civil War.

An abandoned socialist utopia built in the late 19th century.

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

An ornate tower shows off a local artist's architectural flair.

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

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

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

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

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

Translating as "The Jump of the Girlfriend," this stunning waterfall has a tragic legend behind it.

An archeological treasure trove stumbled upon by a couple of children.

The hidden ruins of an old hydroelectric plant reclaimed by nature.

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

An abandoned Indian-inspired mansion.

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

"Alleys of Stone" form natural mazes in Spanish natural park.

Devastated landscape used for hundreds of years by the Romans as their primary mining site.