Mountain region, Baden-Württemberg, southwestern Germany. It extends in a fairly narrow strip about 100 mi (160 km) along the eastern bank of the upper Rhine River, from the Neckar River to the Swiss border. Its highest peak is Feldberg, at 4,897 ft (1,493 m). Its name comes from its dark interior, the higher parts being thickly forested with fir and pine. It is the source of the Neckar and Danube rivers. The setting of many of the Grimm brothers' fairy tales, it is famed for the beauty and charm of its villages and rolling hills. Winter sports are prominent in the area, which also has many mineral springs and watering places, including the spa town of Baden-Baden.