The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

A kindergarten shaped like a cat with a tail that's a slide.

The prison where Hitler wrote "Mein Kampf," and 278 Nazis were later executed for war crimes.

Originally envisioned by King Ludwig II to rival Versailles, Herrenchiemsee's "New Palace" remains half-gilded for lack of funds.

This former Nazi castle was built as a school to train what would have been the future of the Third Reich.

A Nazi concentration camp and Anne Frank's place of death.

Twisted buildings adorn the banks of the Rhine river.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

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

A long spiraling walkway winds through the woods, and around a copper beech tree at the center.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

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

An industrial relic is now one of Europe's most staggering art spaces.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

Salute the leader of the proletariat.

A wildlife paradise, this island is one of the world’s most important habitats for burrow nesting seabirds.

The final resting place of many of Germany's most famous communists.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

One of downtown Berlin's last reminders of its Communist past.

The birthplace of Karl Marx is now a museum dedicated to the communist revolutionary's life and work.

Retirement home for giant obsolete machines.

A quaint Russian village in the middle of a German metropolis.

This former steel and coal plant is now a neon-lit industrial fantasia.

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