It is a vast lagoon, crossed by the waters of Cértima river, a Vouga tributary river. Covered by water lilies, it shelters ducks, as well as other migratory birds. Its shape resembles a rectangle, delimited in the southeast by Piedade village and in the northeast by Requeixo parish. This lagoon is a very beautiful natural area, offering a peaceful environment, typical of the nearby panoramas of Aveiro ria (drowned river valley). Pateira viewpoint is one of the greatest highlights of Fermentelos that opened in 1961.