The capital of Wallonia is Namur, and the most populous city is Liège. Most of Wallonia's major cities and two-thirds of its population lie along the east-west aligned Sambre and Meuse valley, the former industrial backbone of Belgium. To the north of this valley, Wallonia lies on the Central Belgian Plateau, which, like Flanders, is a relatively flat and agriculturally fertile area. The south and southeast of Wallonia is made up of the Ardennes, an expanse of forested highland that is less densely populated.