Seaside ruins of a settlement that date back to the first century B.C.

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

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

This remarkable prehistoric town is full of watchtowers and houses that have withstood thousands of years.

This "flat geyser" bubbles up out of the ground periodically like a disappearing river.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

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

An ancient Roman theatre restored to its former glory in the Spanish city of Cartegena.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This religious complex carved into a cliff is steeped in legends of miraculous stags and the Holy Grail.

The oldest Roman lighthouse still in use.

A medieval village holds a very modern hotel.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Famed architect Antoni Gaudi built this generous thank you gift to a friendly host who housed him during a job.

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

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

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

"Alleys of Stone" form natural mazes in Spanish natural park.

Of course Salvador Dalí lived in a castle...

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

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

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

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