city, North Rhine–Westphalia Land (state), northwestern Germany. It lies along the Wupper River, south of Wuppertal, in the heart of the Bergisches Land, a hilly, wooded district in the lower Rhine River valley. Mentioned in the late 11th century as an estate given to the Hospitallers by the count of Berg, it was chartered in 1808 and absorbed the neighbouring towns of Lennep and Lüttringhausen in 1929. Remscheid specializes in tool manufacture and has machinery, electronics, and chemical industries. Tourism is also important. Remscheid has interesting slate houses, one of which (Haus Cleff) serves as the local museum. The Lennep district—the birthplace of Wilhelm Conrad Röntgen (Röntgen, Wilhelm Conrad), the discoverer of X-rays—has the German Röntgen Museum. The city also features a tool museum and a cluster of performing-arts venues. To the southeast on the Alt River is Germany's oldest dam for supplying drinking water (1891). Pop. (2003 est.) 117,717.