Mannheim, officially the University City of Mannheim, is the second-largest city in the state of Baden-Württemberg, after the state capital of Stutt…Mannheim, officially the University City of Mannheim, is the second-largest city in the state of Baden-Württemberg, after the state capital of Stuttgart, and Germany's 21st-largest city, with a population of around 317,000 inhabitants. The city is the cultural and economic centre of the Rhine-Neckar Metropolitan Region, Germany's seventh-largest metropolitan region with nearly 2.4 million inhabitants.