Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Ancient burial grounds of the wealthy.

Locals rallied to save this beloved mural after someone mistakenly attempted to cover it.

This innocuous-looking button may have been used to assassinate a king.

This collection of Dwarf beech trees were once believed to be enchanted trolls in disguise.

A centuries-old copper mine that once provided two thirds of the world's copper supply.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

Where the writer penned his famous story about a jumping frog.

While not Turkey's deepest underground city, this subterranean redoubt is the largest.

A 19th-century architectural wonder designed by the "father of the skyscraper."

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

Sweden's oldest street has not changed for nearly a millennium.

The original home of the Lego has a huge amusement park dedicated to the iconic plastic toy.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

The world's first combination ski slope and power plant.

Storybook cottage in Beverly Hills was once the site of 1920s silent film studio, affectionately known as "The Witch's House."

A series of abstract, silly sculptures represent the works of a great modern classical composer.

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

One woman's Viking Castle on Lake Tahoe.

A singular collection of hand-built art deco cars are held in a building with style to match.

This historic square in Nepal is home to temples dating back to the third century.

One of the largest Buddhist stupas in the world keeps an eye out in every direction.