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

A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

This amazing abuela became a diehard metal fan late in life and an icon of Madrid's '80s rock scene.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

An ancient Egyptian temple in the middle of Madrid, Spain.

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

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

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

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

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

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

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.

Turntable anonymously received orphans, alms, and groceries.

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

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

This cemetery features modernist statues as strange as its name.

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.

A beautiful but toxic fountain of mercury.