This imposing 20th-century castle was abandoned before it was ever completed.

Communism's topsy-turvy effect on Poland has been brought to life in this wacky tourist trap.

This open-air museum was originally a World War II testing ground for German missiles and rockets.

The oldest wind turbine in Europe, constructed by a group of friends in 1932.

This fairytale medieval church in Poland originally spent centuries in Norway.

This mysterious and once-grand memorial still embodies a remarkable architectural vision.

A mysterious structure left behind on the Polish mountainside, sometimes called "Hitler's Stonehenge".

Naturally formed rock city in Poland.

Home to the world’s oldest seismograph and a four-ton steel ball that makes its own earthquakes.

These beautiful objects represent beautiful ideas.

Goethe's "Faust" was inspired by these rock formations known as the "Devil's Pulpit" and "Witches' Altar."

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.

This proud Teutonic warrior rises out of a German forest heralding a victory and measuring lightning.

On this Polish road, an optical illusion makes cars seem to roll uphill.

A small but immensely extravagant palace built by the "Night King."

Tiny castle in the middle of the Rhine made you pay to pass.

Berlin's old airport.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

This historic stone bridge has an entire neighborhood clinging to its sides.

A century-long search for a church that was never there.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

The world's first and only three-segment bascule bridge folds up into the shape of a capital "N" to let boat traffic through.

Enter the cabin of a life-sized Hindenburg replica.