Pirna (pĭrˈnä) [key], city (1989 est. pop. 47,100), Saxony, E central Germany, on the Elbe River. Manufactures of this industrial city include rayon, paper, glass, furniture, and steel. Nearby are sandstone quarries. Known in 1233, Pirna passed to Bohemia in 1298 and to Meissen in the early 15th cent. The Saxonians surrendered (1756) there to Prussia in the Seven Years War. Noteworthy buildings include a 16th-century Gothic church, the city hall (begun 1555), and Sonnenstein castle (16th cent.).