The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

Spanish architects used seized Muslim gravestones to rebuild parts of the fortress.

A New York–based physician returned home to Spain to build his own elaborate monument to Christopher Columbus.

Rare karst landscape eroded from a flat seabed.

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

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

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

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.

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.

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

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

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