An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

Statues of a fire-breather, a clown, and a whole performing troupe celebrate Luxembourg's creative side.

Some believe that the artist behind this whimsical statue inserted his own likeness as a way to discreetly flip the bird.

Now overgrown, these anti-tank barriers from World War II are sometimes called "dragon's teeth."

Once the local rulers had gone these enchanting ruins housed common folk in an almost real life fairy tale.

This tri-part waterfall is a little bit of fairytale beauty in the heart of Luxembourg's Little Switzerland.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

The bizarre visions of H.R. Giger, tucked away in a Swiss medieval city.

Standing stones found on a construction site are re-erected.

Unable to build support structures on glaciers, the engineers for this tramway were forced to design a unique system.

A rare example of a German cemetery with traditional grave markers dating back several generations.

Giant WWII fortresses that fired 8,000 rounds a minute, now home to thousands of pigeons.

Op-art architecture designed for happiness.

Bizarrely-painted church designed by a controversial artist.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

Double spiral staircases are not unheard of, but they are very rare.

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

Where the lovelorn find a home for their sentimental keepsakes.

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

A wonderfully strange collection of 500+ stuffed frogs doing people things.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

When a supermarket opened up shop within a medieval building it became protected by UNESCO on a technicality.

Formerly Yugoslavia's "forbidden island," this sleepy little city still holds the abandoned remains of military strongholds.

This 15th-century Serbian Orthodox monastery also contained a school for illuminating manuscripts.