This massive subterranean fissure is known as the "underground Grand Canyon."

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

A unique collection of five Roman burial grounds right next to the road.

A piece of the front end of a British cruiser that was used as a block ship in World War I.

Six turbines towering over a wide road for passersby.

Petting this mysterious iron monkey supposedly brings good luck.

Icelandic folklore says this giant boulder was ripped from the mountains and placed at its current location, where it became home to elves.

This scenic Icelandic lava flow is named for a pair of Berserkers who were murdered, according to a famous Saga.

The oldest hall in Iceland was written of in the Sagas and features a centuries-old escape tunnel.

Puffin enthusiasts flock to Europe's largest seabird cliff, which over one million birds call home.

This mountain fissure hides a secret path to a secluded mossy grotto within the rock itself.

The oldest (maybe) swimming pool in Iceland is a stunning oasis built into the side of a lush hill.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

A former plague hospital turned medical museum.

The world's first fish doorbell monitors this water passageway.

Amsterdam's Red Light District leaves little to the imagination.

A bike traffic circle showcasing the works of local graffiti artists.

Only a few walls remain of the last church the Pilgrims used before they sailed to North America.

The oldest statue in the Netherlands has survived relocation, bombardment, and burial.

This 17th-century house has a long and colorful history.

The oldest skyscraper of Europe now stands dwarfed by the surrounding structures.

A bridge that has seen many reiterations over its lifetime.