The antiquity of the extraction of salt on the right bank of the Lima River, between Meadela and Portuzelo, is documented in the Afonsinas Inquiries, which testify that this activity was carried out, in the 13th century, to the places of Portuzelo and even Santa Marta. In fact, the area known today as salterns was, at least until the end of the 18th century, designated by the suggestive toponym of Marinhas, corresponding to a low quota sector, subject to regular flooding due to the tides. Saltern exploration was thus possible due to the clear entry of sea waters into this area of the Lima estuary, which was later hindered by the progressive aggradation of its estuary, verified, at least since the 15th century, with increasing aggravation from the 17th century.

The Portuzelo saltern forms a small saltwater lagoon on the right bank of Lima, having been used since Roman times.