The "Prussian Versailles" that is as glorious today as when it was built.

The prototype for all Nazi concentration camps.

The highest point in Belgium is a staircase to nowhere.

Hiding the longest subterranean river known in the world.

Theme park featuring miniature replicas of European monuments.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

Climb to the top of the world's largest seated bronze Buddha.

A musical instrument played by the sea.

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

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

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

The world's tallest boat lift stands as a massive piece of industrial tourism.

The corpse bride of Portugal.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

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

The castle was reconstructed to fit Kaiser Wilhelm II's romanticized vision of the Middle Ages.

A copy of the Statue of Liberty greets visitors to the birthplace of Auguste Bartholdi.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This modern French ossuary contains the jumbled bones of 130,000 WWI soldiers.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.