The oldest Roman lighthouse still in use.

An eccentric collection of antique items shares space with a prop-quality witchcraft museum.

A 16th-century Andalusian palace.

Mine shafts and hard pastries await visitors at this massive mountain of salt.

A Romanesque tower appears when water levels drop.

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

A science fiction-inspired apartment building designed by a famous Spanish architect.

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

This magical space partly designed by Antoni Gaudi is one of the best examples of romantic gardening in the Mediterranean.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

Abandoned Nazi train station turned underground astroparticle laboratory.

A once-secret library of Freemason history in Catalonia.

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

Mysterious Spanish catacombs of unknown origins.

Stunning Roman aqueduct used for 1900 years and still standing.

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

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

Of course Salvador Dalí lived in a castle...

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

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

An isolated village literally built into the crevices and rock formations of a mountain.

A Spanish town built into the cliffs.