An exact replica of a colossal Olmec head sits atop a pyramid within a Madrid traffic circle.

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

Madrid's last horchata kiosk is a blue-and-white beacon of refreshment.

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

This modest marker near Notre Dame identifies the very center of Paris.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

A relic of World War I that now exist as a piece of public art.

A highly-criticized monument in Budapest has become the site of a makeshift Holocaust memorial.

A diminutive statue that was inspired by the sculptor's own daughter.

A triumphant marble and bronze fountain depicting a 15th-century Hungarian king and his hunting party.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

A two-way chairlift system between Zugliget and the highest point in the city.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

This 1920s Dutch barge is now a floating bookstore.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This modernist bridge highlights the bear as a symbol of Madrid.

A haven for book enthusiasts across the street from Retiro Park.

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

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

Two nations form a rare four-sided border at the peak of a mountain, philosophical questions result.

Former military fort and site of untold horrors during WWII, this island may become the Adriatic's next luxury resort.

A tiny church on a man-made island in the Adriatic.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.