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

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

A display of torture devices used in the Spanish Inquisition and other scourges of medieval Europe.

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

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

Visit a surreal landscape so otherworldly NASA actually used it to train the Apollo 17 crew.

This small museum tucked within a subway station holds pieces from Madrid's past.

A site where “the ravages of the war are more striking…than any other place in contemporary Spain.”

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

Rare karst landscape eroded from a flat seabed.

A Romanesque tower appears when water levels drop.

Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

A 16th-century Andalusian palace.

Volcanic rocks ground down into sand make this Spanish beach as black as night.

Mysterious Spanish catacombs of unknown origins.

Its appearance in "Game of Thrones" may spur on the long-awaited restoration of this medieval shipyard.

A charming Spanish village sits atop this natural limestone overpass.

Stunning Roman aqueduct used for 1900 years and still standing.

Occupied for six centuries by Franciscan Order nuns, this monastery is an amazing ode to Catalán Gothic architecture.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

This Navarrese cave's history of witchcraft and pagan ritual is not just embraced, but recreated each year.

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

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

At the foot of a waterfall lies a peaceful swimming lagoon and evidence of over 60,000 years of human habitation.