A charming Spanish village sits atop this natural limestone overpass.

Partially collapsed lava tube and cave system complete with concert hall, underground pond, and unique albino crabs.

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

Cliffside houses provide a spectacular view from their perch above the valley.

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

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

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

A lush indoor jungle fills this bustling Madrid transportation hub.

This whimsical winery by Antoni Gaudí looks ripped from the pages of a fairytale.

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.

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

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

Bacteria and algae give the salty water its bubblegum hue.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A beautiful but toxic fountain of mercury.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

This burial mound is said to be the final resting place of Russia's first Viking ruler, Oleg of Novogrod.

A museum dedicated to controversial Russian pianist Alexander Scriabin.