Bonn is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about 24 km (15 mi) south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This metropolitan area, Germany's largest, is also the second largest in the European Union by GDP, with over 11 million residents.