Rare karst landscape eroded from a flat seabed.

This small and often-overlooked museum holds some of Spain's finest artistic treasures.

This lucky bronze frog was gifted to Madrid by a casino.

The world's largest wooden structure.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

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

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

Commonly acknowledged as the only public monument to the Devil himself.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

The largest open-air museum in southern Europe, where nature and contemporary art exist in harmony.

This 16th-century watchtower once defended Spain's Atlantic coast from pirates.

This fascinating and poignant museum chronicles every imaginable aspect of Spanish colonialism in the Americas.

In the summer of 1957, a massive architectural exhibition showed off the future of urban living in this German neighborhood.

A bold and controversial statue of a Christmas icon, blending adult undertones with playful humor, stands year-round in a traffic circle.

This iconic cinema is home to Tangier's Cinémathèque and a symbol of the city's vibrant film scene.

The urinal, known by many names and designated as a Norwegian Cultural Heritage Site for its simple and functional design, stands as a testament to old gay history in Norway.

Stormy conditions send jets of seawater bursting through holes in the cliffs.

A spectacular walk on the flank of a gorge.

Thousands of miniature bronze sculptures have taken over this city square creating a unique art installation.

Home to three historic ships from the age of Vikings.

The only female equestrian statue in Washington, D.C. is a 15th-century French heroine.

An astonishingly accurate water clock that doubles as an hourly spectacle in this Berlin shopping area.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.