Mainz, Germany

Mainz sits on the Rhine River in western Germany with about 220,000 residents and serves as the capital of Rhineland-Palatinate. The Romans founded the city as Mogontiacum in 12 BC, making it one of Germany's oldest settlements. Johannes Gutenberg invented the movable-type printing press here around 1450, and his 1455 Gutenberg Bible is displayed in the 1620 Gutenberg Museum. The six-towered Cathedral of Saint Martin, completed in 975, ranks among the three imperial cathedrals of the Holy Roman Empire. Each February, the city also hosts one of Germany's largest carnivals, a tradition that began back in 1838.