Religious dwelling in a Spanish volcano.

Abandoned 18th century weapons factory in the Aezkoa Valley.

An arresting arch punched straight through a mountain provides one of the most scenic spots, and challenging climbs, on the planet.

The ruins of an ancient stadium that hosted gripping chariot and horse races.

This abandoned, turn-of-the-century astronomy hub is now the subject of more photographs than it ever took.

Semi-mystical manmade towers of rocks decorate this rocky seaside.

A small church ornamented with medieval erotic sculptures.

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

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

The remains of an encyclopedic sculpture garden later used as an internment camp.

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

Mysterious face-like images that appeared within an Andalusian house are surrounded by legends of the paranormal.

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

A series of recreated fortifications mark George Orwell's path through the Spanish Civil War.

A modernist church in an ancient village.

This beautifully verdant lagoon is tucked below a massive volcano in a crater atop a black pebble beach.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

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

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

An outsider folly near Madrid.

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

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

An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

A contemporary art installation housed within a Gothic cathedral.