The streets of a sleepy Spanish town proudly exhibit some of the world's finest graffiti.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

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

This species of wild goat stars in witchy legends and frolics among the park's eerie rock formations.

Stuck in the middle of a modern Madrid city block are the remains of a 19th century sports complex.

A completely underwater art museum sends a stark message about humans' impact on the environment.

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

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

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

A landscape decorated with enormous skull sculptures.

A lush indoor jungle fills this bustling Madrid transportation hub.

This former Baroque palace on the historic Calle Montcada is a rare architectural gem and was once the meeting place of an aristocratic scholarly society.

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

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

Famous for its bio-luminescent inhabitants, known as "Dismalites" .

One person's lost luggage is another person's treasure.