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

The last bastion of Roman presence north of the Alps looms over a German town.

This 600-year-old home seems to defy physics.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

Legendary site where an evil bishop was devoured by rodents.

This tremendous timepiece was once the largest cuckoo clock in the world.

The final resting place of the famed German pilot, the "Red Baron."

A rare water-powered funicular, it uses a huge tank of water and gravity to do its work.

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

A memorial for a young woman and her ghost, which are claimed to have caused countless deathly shipwrecks.

A ruined castle stands atop a hill surrounded by dragon lore.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

This small condiment museum makes all manner of mustards with a 200-year-old mill.

The small alleys in Lübeck's Old Town are a result of medieval urban sprawl.

Twelve sweet, nutty, life-sized statues are housed in this second-story shrine to almond paste.

The world's oldest rose is so tough it survived being bombed in World War II.

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

Berlin's old airport.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

Cold war icon and onetime "hole" in the iron curtain.

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

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.