It is located in the province of Western Finland and is part of the Satakunta region. The municipality has a population of 13,531 (30 September 2012) and covers an area of 422.52 square kilometers (163.14 sq mi) of which 21.82 km2 (8.42 sq mi) is water. The population density is 33.77 inhabitants per square kilometer (87.5 /sq mi)
