This massive fiberglass Gulliver turns every visitor into a Lilliputian.

The earliest known map to show America, discovered by accident at a Paris bookshop.

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

A once-secret library of Freemason history in Catalonia.

Moorish signal station on a stratgic rocky outcrop.

Bold black and white motifs of life and death add a dramatic flair to this 17th-century crypt.

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

A Romanesque tower appears when water levels drop.

Numerous sculptures set along hiking trails symbolize and idealize the relationship between man and nature.

Of course Salvador Dalí lived in a castle...

A completely underwater art museum sends a stark message about humans' impact on the environment.

Stunning Roman aqueduct used for 1900 years and still standing.

Village situated on a narrow volcanic escarpment.

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

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

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

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

Abandoned Nazi train station turned underground astroparticle laboratory.

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

One of Europe's largest supercomputers is housed inside of a disused chapel.

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

Mysterious Spanish catacombs of unknown origins.

This Funeral Hearse Museum represents the finest in cadaver transportation.

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