Historic medieval fortified city in southwest France.

The prototype for all Nazi concentration camps.

Some of the clearest water anywhere in the world.

This one-time health resort was used by aristocrats around the world.

An eerie, derelict amusement park in Berlin.

Fall down the rabbit hole into a surreal journey of human consciousness "from ass to soul."

Highly spherical boulders on the shores of New Zealand.

An old hill fort covered in over 100,000 crosses is a symbol of Lithuanian nationalism and beliefs.

Sweet Willy, at 30 feet tall, is the world's biggest beagle.

"World machine" built by an untrained Austrian farmer.

An amusement park on the grounds of an unused nuclear power plant, with a swing ride inside the cooling tower.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

A gargantuan crystal kingdom.

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

Ride a dragon train into a world of dwarves.

Rippling sand dunes frozen in the Arizona rock.

A seemingly endless landscape of pure salt stretches far across Bolivia.

The largest stone moai on Rapa Nui.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

Virgil's many-mouthed gateway to the underworld.

Free candle-lit art gallery, accompanied by a live piano score.

Beyond being incredibly fun, not much can be said about the Hole with certitude.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

Two stunning 17th-century libraries and a cabinet of curiosities.