A New York–based physician returned home to Spain to build his own elaborate monument to Christopher Columbus.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

These primitive rock paintings include a very beloved depiction of a woolly mammoth.

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

The largest medieval water tank on the Iberian Peninsula is preserved beneath the Cáceres Museum.

Lava stone structures possibly dating back to the 19th century may have been a stopping point for voyagers between ancient Egypt and the Mayan Civilization.

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

The walls of these four caverns are filled with art that dates back to the earliest human presence in Europe.

An arresting arch punched straight through a mountain provides one of the most scenic spots, and challenging climbs, on the planet.

The atmospheric ruins of a historic church can be found on a hill above the city of Oviedo.

A spectacular walk on the flank of a gorge.

The ruins of a 2,000-year-old Roman fishing village perched on one of the best beaches in Spain.

A modernist church in an ancient village.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

Beautiful tiles decorate many of the town's surfaces and stand testimony to its glorious artistic history.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

A huge cathedral single-handedly constructed by one eccentric monk.

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

This 7,000-year-old megalithic wonder covered by a Franco-era reservoir emerges in times of drought.

This amended headstone marks the grave of a participant in one of the most successful military deceptions of all time.

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

This 19th-century fountain's namesake animal isn't what you think it is.

A whimsical garden of outsider art in the Spanish countryside.

Stormy conditions send jets of seawater bursting through holes in the cliffs.