The 2,500 year-old Technicolor town of Passau, Germany, is chock-a-block with a rainbow-bright mix of buildings befitting a Mediterranean village, as it was once part of the Roman Empire. Make no mistake — this is still Germany. Nicknamed the “City of Three Rivers,” Passau is where the Inn, Ilz, and Danube rivers join together to form the Bavarian region’s triple threat of charm. Most river cruise ships and luxury barges dock at the waterfront, a short walk from Old Town.