Eschweiler (ĕshˈvĪlər) [key], city (1994 pop. 55,790), North Rhine–Westphalia, W Germany, near Aachen. Its manufactures include lignite, iron, steel, rubber goods, limestone, textiles, and plastics. Known in the 9th cent., Eschweiler passed to the duchy of Jülich in 1420 and to Prussia in 1815. Noteworthy structures include the Church of Saints Peter and Paul (dating partly from the 12th cent.) and a 15th-century castle.