A wall of chewing gum moonlights as collective art.

A giant Troll lurks under one of Seattle's oldest bridges.

This iconic science fiction house still looks like something from the future.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

France's most famous cemetery, with some of its most curious tombs.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Eighty million natural history specimens call this gargantuan museum home.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

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

An artificial date palm stands as a memorial to Warsaw's Jewish community.

This 13th century Gothic brick castle is the largest in the world by surface area.

A collection of old neon signs from all over Poland line a secluded courtyard.

The silly symbol for an underground protest group is now scattered around the city.

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.