The surviving remnants of a destroyed medieval church now stand in a public park.

A hidden medieval crypt where a famous legend says the devil used to teach black magic.

This enchanting green space houses a labyrinth lined with toxic plants.

This enigmatic artifact is a rare depiction of an ancient Iberian noblewoman.

The extensive relics of an ancient Roman and Phoenician fish processing plant hide in a town park.

A reproduction of the famous prehistoric cave paintings is hidden underground at the National Archaeological Museum.

The unfinished final resting place of some of Spain's most prominent politicians.

This enormous censer uses a pulley system installed over 400 years ago.

This influential Renaissance-era library was once the haunt of kings and monks.

One of Antoni Gaudí's least-visited works, an homage to Catalan patrimony that mixes neo-Gothic with Modernista forms.

An early 20th-century bullring converted into a modern shopping center.

An out-of-place grove of sequoias thrives in northern Spain.

A historic Christian shrine nestled within a spectacular natural cave.

Part of the medieval watchtower is displayed in an otherwise ordinary parking garage.

A curious carving hides on a marble column in the Mosque-Cathedral of Córdoba.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

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

A once-secret library of Freemason history in Catalonia.

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

Mysterious Spanish catacombs of unknown origins.

Stunning Roman aqueduct used for 1900 years and still standing.

The final resting place of the great navigator, or maybe his brother.

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

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