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

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

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

This 47-story "M" needed 20 years to be completed

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

An abandoned Indian-inspired mansion.

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

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This ancient Spanish castle sits high upon a hilltop.

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

A charming Spanish village sits atop this natural limestone overpass.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

Moorish signal station on a stratgic rocky outcrop.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

One of the largest ossuaries in Spain is packed from floor to ceiling with bones.

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

The abandoned ruins of a beautiful medieval castle just outside Barcelona.

Abandoned Nazi train station turned underground astroparticle laboratory.

Mysterious Spanish catacombs of unknown origins.

Stunning Roman aqueduct used for 1900 years and still standing.

A Franco-era dam flooded (almost) everyone out of this centuries-old Aragonese town.

Village situated on a narrow volcanic escarpment.