Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

Sweden's first nuclear reactor, R1, can be visited 25 meters underground.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Surreal riveted sea forts once protected the Kent shores from German attack.

Come for the fried chicken, stay for the history at Oklahoma's oldest bar.

The only remaining sod house Oklahoma built by a homesteader in 1894.

This unique landscape is the only place in the world to dig for hourglass-selenite crystals.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

A close look reveals that the Scottish monument is just slightly off-kilter.

A beautiful gorge filled with streams and waterfalls.

Towering sandstone rock formations where 'The Chronicles of Narnia' was filmed.

Two gushing waterfalls of hot spring water within a block of each other.

Nestled in the hills of Tuscany are gorgeous, multicolored hot springs.

In 1943 the British military took control of this village, telling residents they had to leave temporarily. The villagers were never allowed to return.

Hidden in the forest are the crumbling, graffiti-covered remains of the factory where most of Germany's explosives were produced during World War II.

This disused boat elevator was saved from the scrap heap so that visitors could tour its rusting skeleton.

This bunker in northern France was built by Nazi German forces with the intention of launching up to 50 V2 rockets at London each day.

Walk through spectacular aisles of hanging meat and wagon wheel–sized cheese at the world's largest wholesale food market.

This little gallery is devoted to one small town's passion for a very special cheese.

The cheese slicer may be a Norwegian invention, but the biggest ones in the world are found in Sweden.

A humble ancient well where Scottish knight, Sir William Wallace, took his final drink.

A UFO-shaped event building originally intended to be a science museum showcasing the future.

This World War II-era bunker hides between medieval chapels in Nijmegen's city center.

This highrise residential building looks mundane, but hides a water tower and WWII bunker.