The Pataias lagoon is the main wetland in the municipality of Alcobaça, constituting a Biodiversity hotspot in the coastal pine forest. It is very close to the northern limit of the Municipality of Alcobaça, more precisely in the Parish of Pataias.

The water mirror has a major axis of around 400m and a minor axis of around 125m. The lagoon ends in a water line that extends a few kilometers to the North. This water line is the only existing drainage, so its flow depends entirely on precipitation.
The Lagoon is part of a succession of wetlands that mark the Portuguese coastline, being located on one of the main migratory axes of waterfowl that cross mainland Portugal (Rio Minho, Ria de Aveiro, Baixo Mondego, Lagoa de Óbidos, Tagus Estuary, Sado Estuary and Santo André Lagoon), being essential for resting, sheltering and feeding wintering birds.
The functions of wetlands (natural and socio-cultural) are, for the most part, irreplaceable and, if replaceable, very costly. Therefore, it is in every interest to conserve the existing heritage. On the other hand, the uniqueness of the system in the region reinforces its importance and the urgent need to conserve it. This responsibility must be shared by all citizens since leaving the natural heritage to future generations is a transversal duty to society. By the way: we currently enjoy the lagoon because past generations knew how to appreciate it.

It is located in the parish of Pataias, located northwest of this village.

Text Source: https://portaldomunicipe.cm-alcobaca.pt/menu/587/lagoa-de-pataias.aspx
Image source: https://www.cm-alcobaca.pt/pt/2722/lagoa-de-pataias.aspx