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

An early 20th-century bullring converted into a modern shopping center.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

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.

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

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

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

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

Mountain where Jesus was first tempted by the Devil.

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

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

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.