Founded in the mid-9th century, Ulm enjoyed a long history as a free imperial city, ruled only by the Holy Roman Emperor with no pesky princes in between. An important trade town for centuries, Ulm was also the birthplace of Albert Einstein. Rising 530 feet, Ulm Minster has the world’s tallest steeple, the top of which can be reached via 768 steps. Ulm’s younger sister city, Neo Ulm (or New Ulm) lies just across the Danube River and is part of Bavaria rather than Baden-Wurttemberg.