Mannheim is a city in the southwestern part of Germany, the third-largest in the German state of Baden-Württemberg after Stuttgart and Karlsruhe. Mannheim is among the twenty largest cities in Germany, with a 2015 population of approximately 305,000 inhabitants. The city is at the centre of the larger densely populated Rhine-Neckar Metropolitan Region which has a population of 2,400,000 and is Germanys eighth-largest metropolitan region. Mannheim is located at the confluence of the Rhine and the Neckar in the northwestern corner of Baden-Württemberg. The Rhine separates Mannheim from the city of Ludwigshafen, just to the west of it in Rhineland-Palatinate, and the border of Baden-Württemberg with Hesse is just to the north. Mannheim is downstream along the Neckar from the city of Heidelberg. Mannheim is unusual among German cities in that its streets and avenues are laid out in a grid pattern, leading to its nickname "die Quadratestadt". The eighteenth century Mannheim Palace, former home of the Prince-elector of the Palatinate, now houses the University of Mannheim. The city is home to major corporations including Daimler, John Deere, Caterpillar, ABB, Fuchs Petrolub, IBM, Roche, Reckitt Benckiser, Unilever, Phoenix Group, Siemens, and several other well-known companies. In addition, Mannheims SAP Arena is not only the home of the German ice hockey record champions the Adler Mannheim, but also the well-known handball team, the Rhein-Neckar Löwen. According to the Forbes magazine, Mannheim is known for its exceptional inventive power and was ranked 11th among the Top 15 of the most inventive cities worldwide. The New Economy Magazine elected Mannheim under the 20 cities that best represent the world of tomorrow emphasizing Mannheims positive economic and innovative environment. Since 2014, Mannheim has been a member of the UNESCO Creative Cities Network and holds the title of "UNESCO City of Music". Mannheim is a Smart City; the citys electrical grid is installed with a Power-line communication network. The citys tourism slogan is "Leben. Im Quadrat.". The civic symbol of Mannheim is der Wasserturm, a Romanesque water tower completed in 1886 that rises to above the highest point of the art nouveau area Friedrichsplatz. Mannheim is the starting and finishing point of the Bertha Benz Memorial Route.