Long tunnels run under the ancient chariot racing circuit to the tower.

A five-square-mile slice of Spain on the Mediterranean coast of North Africa.

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

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

According to the Guanches, the aboriginal people of the Canary Islands, the king of evil lives inside this volcano.

Giant topiary dog once played a role in a terrorist bomb plot.

Peek into a cave of giant, glimmering crystals.

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

Holy Grotto of Montserrat Monastery holds one of Europe's mysterious black Madonnas.

This line of 12 tower mills described in the story of Don Quixote is among the most iconic landscapes in Spain.

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

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

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

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

The oldest Roman lighthouse still in use.

One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

A lush oasis full of vibrant plants and striking geometric displays.

One man's remarkable private collection of art from around the world.

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

Perhaps the most spectacular grotto along the Algarve coastline.

The lost Latin words were reconstructed using the holes from the nails that once pinned them in place.

This stunning and ethereal mural symbolizes the beauty, unity, and diversity of humankind.

Come face to face with the ferocious visage of the serpent-headed mother goddess of the Aztecs.

The turquoise-studded skull of a long-dead Aztec man sits within Mexico City’s Museum of Anthropology.