The sunken structure looks like the victim of a catastrophic flood.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

Historic medieval fortified city in southwest France.

A miniature city, once ruled by the Queen of the Netherlands.

The giant scales in this museum can still tell if someone is one of the devil's brides just by weight.

The tallest mountain in mainland Netherlands isn't actually very tall.

It has an American Dream Car exhibit, Europe's largest Formula One collection, and many, many mannequins.

This monument to those fallen in the World Wars is accompanied by a U-boat that Germany bought for a Deutsche Mark.

On the highest peak in the Harz Mountains, science and the occult faced off in a failed attempt to turn a goat into a boy.

An officers prison camp believed to be impregnable by the Germans saw over 30 successful escapes.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

This Roman quarry once held secret masses and smuggler's contraband and is now home to rare species of bats.

It's good luck to be mocked by this monkey.

Germany's Glienicke Bridge has a shady history of clandestine meetings, espionage, and spycraft.

Enter the cabin of a life-sized Hindenburg replica.

This abandoned coliseum was intended to be a grand Nazi rallying ground before it was halted at the end of the war.

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

The prototype for all Nazi concentration camps.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

This "floating railway" is one of the world's oldest monorail systems.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

6000-year-old site covered in more than 50 megaliths.

Seat of the Duke and Duchess of Devonshire for centuries.