This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

Once the grandest synagogue in medieval Spain, it now stands as a memorial of the 15th-century Jewish exile.

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

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

Built to power trains, the engines in this building provided the entire city of Madrid with electricity during the Spanish Civil War.

A pair of gigantic baby heads greet passengers at Atocha Station.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

The remains of the second-oldest zoo in Europe can be seen within these library gardens.

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

The lengthy skeleton of one of the tallest Spaniards of all time is on display in Madrid.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

Five million people are laid to rest here, more than the population of Madrid itself.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

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

Vibrant street art created with mixed media.

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

For decades, Puerta del Sol has been illuminated by a giant, guitar-wielding bottle of sherry.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

A unique seaside cave where Aleister Crowley faked his own death.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Barcelona's only remaining tram system takes riders to the Tibidabo funicular.

This home designed for chocolate magnate Antoni Amatller is an exquisite treasure-box of Catalan Modernism.