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

Blue-green pools and smooth stones comprise one of Spain’s most idyllic hidden wonders.

Remote, beautiful, and stigmatized, Las Hurdes is Spain's version of Appalachia.

Disturbing winged beings decorate the walls of this strange abandoned hermitage.

This 7,000-year-old megalithic wonder covered by a Franco-era reservoir emerges in times of drought.

A neighborhood park in the city of Cáceres hides what some believe are revolutionary examples of Neanderthal cave art.

An abandoned mine now resembles a post-apocalyptic landscape of derelict buildings and blood-red pools of water.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

Spain's stunning solar energy plant.

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

Single runway interrupted by a busy road that cuts across its middle.

There was a top secret plan during World War II to seal a group of soldiers inside the rock.

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

Moorish signal station on a stratgic rocky outcrop.

A micro-communist utopia in Spain with no police, no mortgages and full employment.

Holding the current title of "biggest chair in the world," it stands with little fanfare in Lucena, Spain.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

This surreal-looking tree pruned more than 1,000 years ago is still producing olives for oil.

This abandoned gold mine found a second life as a post-apocalyptic film set.

Bacteria and algae give the salty water its bubblegum hue.

This 15th-century aqueduct with distinctive pointed arches was used for irrigation in the Vinalopó valley.

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

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

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