Baden-Wurttemberg’s second-largest city after Stuttgart, Mannheim lies at the confluence of the Rhine and Neckar Rivers and is rare among German cities for its layout, a grid pattern (or “quadrates”) similar to those found in North America. The grid was originally plotted in 1606 and emanated from Friedrichsburg fortress, which later became the site of Mannheim Palace. Today, it partly houses the University of Mannheim. The city’s iconic water tower and its beautiful Luisenpark are must-sees.