Ruhr City is a metropolitan area in Germany, located in the state of North Rhine-Westphalia. It is made up of several cities, including Essen (5 letters), Hamm (4 letters) and Herne (5 letters). These cities are all part of the Ruhr Valley, an area known for its industrial heritage and its many cultural attractions. The Ruhr City is one of the most populous metropolitan areas in Europe, with over 5 million people living in the region.