The natural park was established on 9th december 1987.

It surrounds about 60km of coast in eastern Algarve between Ansao and Monta Rota, and its surface is about 18.400 ha, with the districts of Loulè, Faro, Olhao, Tavira and Villa Real de Sant Antonio. The biggest part of this area corresponds to the barrier island system of Ria Formosa, a costal dune barrier, running parallel to the land, that defends a shallow warm water lagoon divided into a labyrint of saltmarsches, channels, tidal flats and islets. It is a vital area for birds and for waterfowl and it has the important purpose to protect the fauna, the flora and landscape that are charateristics of the area. Birds usually came from northern and central Europe wintern into this area infact Ria Formosa is a stop point in the migration journey between Europe and Africa. In this area we can find particular duck species such as the Wigeon, the Shaveler, the Teal, the Pochard,or some Waders such as the Dunlin, the Bar-Tailed Godwit, the Curlew and the Gray Plover. It provides also for the Purple Gallinule that was chosen as the symbol of the natural park.

The dunes, the salinas, the pine woodlands, the saltmarsches are also very important features displaying representative aspects of the ecosystems of Ria Formosa. The lagoon is a sort of " nursery "for the oceanic species such as the Gilhead, the Common Bass, White Bream and the Shrimp that spend their early stages of development. In Ria Formosa, especially in the lagoon, lives a population of 7.500 people that during the summer can triple. They work in activities related to fishing, fish and shellfish forming and salt production. Ria Formosa has also important buildings that were restored such as a tidol mill a traditional farmhouse, the villa that was built by Joao Lucio a locally famous poet of the beginning of the century, the Roman Ruins and a training ground specialized in the portuguese water dog.