Antuã is a Portuguese river, located on the Aveiro region. Portugal, officially the Portuguese Republic (República Portuguesa is a country on the Iberian Peninsula. Aveiro (aˈvɐjɾu is a city of some 57000 people and a municipality in Portugal with a total area of 199 It is the most important tributary of the Ria de Aveiro after the Vouga river. River Vouga is a river in the Center region of Portugal. The source of the Vouga is the Chafariz da Lapa at a height of 864 m in the parish of Quintela, municipality Its name is linked to the former name of Estarreja: Antuão or Anterão. Estarreja ( pron (ɨʃtɐ'ʁɐjʒɐ or) is a municipality in Portugal with a total area of 108 It has its source between Romariz and Fajões, near S. Romariz is a Portuguese parish located in the municipality of Santa Maria da Feira. João da Madeira, and it ends west of Estarreja, on the waters of the Ria de Aveiro. The main towns near its banks are S. João da Madeira, Oliveira de Azeméis and Estarreja. Its main tributary is the Ínsua. It has a total length of about 38 kilometers.