Noreña is a municipality in the Autonomous Community of the Principality of Asturias, Spain. It is surrounded by the municipality of Siero. It is t…Noreña is a municipality in the Autonomous Community of the Principality of Asturias, Spain. It is surrounded by the municipality of Siero. It is the smallest municipality in Asturias and the second smallest in Spain, and one of the ones with the highest per capita income and population density in the Principality. Noreña is also the name of a parish in the municipality, and the municipal capital.