Riola Sardo, Arriora or Arriola in the Sardinian language, is a comune (municipality) in the Province of Oristano in the Italian region Sardinia, located about 100 kilometres (62 mi) northwest of Cagliari and about 11 kilometres (7 mi) north of Oristano. As of 31 December 2004, it had a population of 2,132 and an area of 48.2 square kilometres (18.6 sq mi).[3]