"Only the devil could play golf here."

Odd outsider art installations surround a Gold Rush-era ghost town.

An architect's childhood fantasy treehouse made real.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

The celebrated eyesore created by starry-eyed sweethearts.

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

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

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 whimsical bridge adorned with decorative dragons.

Gigantic Romanian salt mines used to heal respiratory conditions.

Descend into the tunnels to experience the life of a coal miner.

A giant bug impaled on a 75-foot-tall needle.

Theme park featuring miniature replicas of European monuments.

Climb inside an iron crystal magnified 165 billion times its normal size.

Lavish royal estate punctuated with heated greenhouses.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

From Tintin to the Smurfs, Europe's greatest graphic icons are celebrated in a grand Art Noveau gallery.

Brussels' favorite peeing boy has a sister.

A little sculpture with a large wardrobe.