This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Geological storytelling.

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

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

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

A breathtaking canyon offers stunning views and frightful pathways through an ecological paradise.

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

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

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

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

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

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

Stunning Roman aqueduct used for 1900 years and still standing.

An isolated village literally built into the crevices and rock formations of a mountain.

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

Village situated on a narrow volcanic escarpment.

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.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

An architect transformed this abandoned cement factory into his castle-like workshop.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.