Herisau (hāˈrĭzou) [key], town (1990 pop. 15,624), capital of Appenzell Ausser-Rhoden half canton, NE Switzerland. Cotton textiles, paper, wood, blown glass, machinery, and other metal goods are manufactured there. The town is also a cattle market and a popular tourist resort. Among its historic monuments is a church with elements dating back to the 10th cent.