Abandoned Nazi train station turned underground astroparticle laboratory.

Village situated on a narrow volcanic escarpment.

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

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

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

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

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

Bacteria and algae give the salty water its bubblegum hue.

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

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

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

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

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

Long tunnels run under the ancient chariot racing circuit to the tower.

Stunning Roman aqueduct used for 1900 years and still standing.

Super Robot anime statue guards a forgotten suburban development in Tarragona.

A darkly erotic open-air statuary in Catalonia.

Of course Salvador Dalí lived in a castle...

A Romanesque tower appears when water levels drop.

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

Abandoned waterpark turned counter-culture mecca.

Cursed swimming pool left abandoned is now a favorite of filmmakers and ghost hunters.

A paradisical gorge with rapids, waterfalls, and wildlife whose raw beauty is the stuff of CGI movies.

Mysterious "dots" seen from a satellite in southeast Peru.