Osterwieck is a historic town in the Harz district, in the German state of Saxony-Anhalt. The municipal area stretches along the river Ilse, nort…Osterwieck is a historic town in the Harz district, in the German state of Saxony-Anhalt. The municipal area stretches along the river Ilse, north of Wernigerode and the Harz mountain range. The Altstadt with St. Stephen's Church is a stop on the scenic German Timber-Frame Road and on the Romanesque Road.