The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

Lavish royal estate punctuated with heated greenhouses.

This ghost town in Belgium will lose its street art when it ceases to exist.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

Huge concrete structures designed as an early warning system for Britain to detect enemy aircraft.

Largest lake in Great Britain measured by surface area.

Millions of years of oxidation make a drive down this winding Death Valley road surprisingly colorful.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

Ancient mysterious ruts carved in the bedrock.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Folklore and history carved into Brittany's coast.

This French "sea of rocks" is packed with stunning rock formations and its own medieval castle.

If they push on just the right spot, even the weakest person can move this titanic boulder.

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

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

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Museum dedicated to the terror regimes of Hungary.

This abandoned five-star hotel is now a five-star urban exploration destination.

A fantastic castle rumored to be the birthplace of King Arthur.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

This crumbling, graffiti-covered mansion sits tantalizingly within reach of the proletariat who frequent a public park.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.