Piarnu (Castrillón)Piarnu is one of eight parishes (administrative divisions) in Castrillón, a municipality within the province and autonomous community of Asturias, in northern Spain.The population is 791.VillagesSource: L'Alvarina Buxande La Cangueta El Cascayu La Corredoria El Cuadru La Llaguna La Machuquera Moire Orbón Pipe Pulide La Ramera de Riba Romadoriu La Salguera Teboyas