Single runway interrupted by a busy road that cuts across its middle.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

This 2,000-year-old stone maze is one of the oldest in the country, but its purpose is still a mystery.

This patch of land is home to Sweden's largest burial mound, allegedly belonging to a mythical king.

Stockholm's deepest subway station is also a stunning ecological wonder.

It houses the remains of a 17th-century version of the Titanic.

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Walk into an underground archeological dig, the site of the Roman Forum that was once the center of Valencia.

Vibrant street art created with mixed media.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

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

A lush indoor jungle fills this bustling Madrid transportation hub.

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

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

This cemetery features modernist statues as strange as its name.

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

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.