A modernist church in an ancient village.

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

The Gaudí-inspired building that was the start of Terrassenc modernism.

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

Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

Abandoned waterpark turned counter-culture mecca.

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

Stunning Roman aqueduct used for 1900 years and still standing.

This house's itty bitty size means no humans allowed.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Commonly acknowledged as the only public monument to the Devil himself.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

Bacteria and algae give the salty water its bubblegum hue.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

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

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

These striking ruins of a castle resemble a ship's stern.

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

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

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