Bonn

Bonn, officially the Federal City of 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.Wikipedia

North Rhine-Westphalia or North-Rhine/Westphalia, commonly shortened to NRW, is a state in Western Germany. With more than 18 million inhabitants, it is the most populous state in Germany. Apart from the city-states, it is also the most densely populated state in Germany. Covering an area of 34,084 km2 (13,160 sq mi), it is the fourth-largest German state by size.Wikipedia