The Ria Formosa coastal lagoon system constitutes the southernmost end of the Portuguese coast. It consists of a lagoon protected from the direct action of the open sea by five barrier islands and two peninsulas spatially distributed to produce a cuspate shoreline that extends over 55 km. The barrier islands are highly dynamic systems in a constant process of recycling mostly driven by inlet breaching and migration. The backbarrier area consists mainly of tidal flats, salt marshes, small sandy islands, and tidal channels.
The geographical, geomorphological and climatic conditions of Ria Formosa made the lagoon a breeding and transit area for fishes and birds. As a result, the area is internationally recognized and protected within the Wetlands of International Importance (Ramsar) Convention and the Birds and Habitats Directive (Natura 2000 Network). At a National level, Ria Formosa was integrated within the Natural Park network of Portugal in 1987. The beach and dune system occupies 13% of the total system among which more than 6% are grey dunes a priority habitat type. The rest of the system is low-lying lagoon area, such as, marsh and intertidal flats, with a great percentage of important habitats like the Zoostera marina and Zoostera nolti meadows. A large part of Ria Formosa is in a natural state, with the main economic activities (aquaculture and salt extraction) been developed on only 12 % of the lagoon.
The number of residents inhabiting the Ria Formosa drainage basin increased remarkably from circa 99,950 to 159,530 between 1970 and 2001. The drainage basin sustains different land uses (e.g. urban development, animal husbandry, industrial units, and agriculture). Urban development inside Ria Formosa is, however, relatively low and occupies a very small portion of the system concentrated mainly in 5 small villages. Most of the villages are located at the backbarrier area of the barrier islands. The only location with access by car is Praia de Faro, near the University of Algarve.
The lagoon is extensively used for recreational purposes. Tourism in the area is essentially beach related, although golf, yachting, water sports and game fishing are also important tourism and recreational activities. Additionally, the lagoon supports other human activities with economic importance, namely aquaculture, shellfish farming, salt production, and fishing.