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

Catalonia Tradition: Beating the hollow Christmas log until it defecates in your fireplace.

A once-secret library of Freemason history in Catalonia.

18th century anatomical amphitheater of the Royal College of Surgery of Barcelona.

Turntable anonymously received orphans, alms, and groceries.

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

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

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

Week-long block party becomes a competition for the best decorated street.

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.

One of Europe's largest supercomputers is housed inside of a disused chapel.

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

Mountain where Jesus was first tempted by the Devil.

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

This imposing modern citadel started out as a home renovation project.

Cursed swimming pool left abandoned is now a favorite of filmmakers and ghost hunters.

The Gaudí-inspired building that was the start of Terrassenc modernism.

This chest hospital with a dark, haunted past serves as a fitting set for horror films and a paradise for ghost hunters.

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

An ornate tower shows off a local artist's architectural flair.

An independent naturist colony amidst 1000-year-old ruins.

Museum of amazing old toys and automata.

Archaeological site of Iberian people ruins.