The Ruhr is a river in western Germany. It flows into the Rhine River. It is 218 kilometres (135 mi) long. The Ruhr begins near the town of Winterberg and flows into the Rhine River near Düsseldorf. Winterberg is located in the Sauerland region and Düsseldorf lies in North Rhine-Westphalia in the west of Germany. It runs through Arnsberg, Iserlohn, Schwerte, Bochum and Essen, among other cities.
Several Ruhr-area cities joined the Hanseatic league during the middle ages. The Ruhr became a center for business and industry. Beginning in the mid 14th century coal was mined along the Ruhr. It became a center for coal and steel production in Germany for over 200 years. In the mid 20th century coal and steel industries came to an end. The buildings were then used for cultural events and entertainment purposes.