A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

Village situated on a narrow volcanic escarpment.

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

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

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

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.

A stately palace has been converted into the world's largest cannabis museum.

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

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

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Wonderland replication in progress by one persistent man.

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

Bacteria and algae give the salty water its bubblegum hue.

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

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

An unusual stroll through gentlemen's erotica demonstrates that pornography is timeless.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

A beautiful but toxic fountain of mercury.

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

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

This semi-secret storybook hedge maze is also the oldest garden in the city.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

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