Novocherkassk (nôˌvəchĭrkäskˈ) [key], city (1989 pop. 188,000), SE European Russia, on the Aksai River (the right tributary of the Don). It manufactures locomotives, machine tools, mining and building equipment, and chemicals. Founded in 1805, it remained the administrative center of the Don Cossacks until 1920. Novocherkassk was the site of the hetman's palace and has a Don Cossack historical museum.