region, North Rhine-Westphalia (North Rhine–Westphalia) Land (state), western Germany, along the east bank of the Rhine River, between the Sieg River south of Cologne and the Ruhr River near Duisburg, merging into the Sauerland, a hilly region to the east. The Bergisches Land extends over the area that was the medieval county and duchy of Berg. It comprises a gentle plateau with little agriculture but numerous industries. It also is a popular recreational area.