World's strongest whirlpool.

Home to three historic ships from the age of Vikings.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

The prototype for all Nazi concentration camps.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

A whimsical bridge adorned with decorative dragons.

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

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A miniature train-ride through Slovenia's largest cave system.

100 year tradition of fist fights, marked by marble footsteps.

Go inside to really appreciate this 500-year-old technological masterpiece.

The plague quarantine island home to the alleged "Vampire of Venice."

One of the largest caves in the world open to the public.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

One of the most unusual geological features, recognizable from a dozen hit movies.

"Only the devil could play golf here."