The Bahía de Cádiz natural park covers an area of 105 square kilometres, north, east and south of the city of Cadiz. The bay itself is shallow and is a former ancient estuary that was fed by the Rio Guadalette and San Pedro. Around the edges of the bay, apart from some superb beaches, are marismas, or intertidal extension marshes that have been utilised since before the Romans arrived for salt production.
The area is tidal, and plant life has to be salt resistant. Cord grass, glasswort or maritime purslane, among others, have an important presence, whilst in the transition of the marshland into firm land there are grasses such as rostraria and barren brome On the intertidal plains, rich in nutrients, there are submerged meadows of gracilaria and algae, such as ulva linza and the sea lettuce. These seafloors, rich in food, halfway between The Gibraltar Strait and the Doñana marshes, play an important role in the migratory movements of birds. They enable many birds to winter on the coast: mud-dwelling birds, waders, seagulls, anatidae, coots and water pullets, osprey, common and little terns, that make up some of the largest colonies of the Iberian Peninsula, and increasingly larger numbers of cormorant, are good examples. Shellfish also plays an important role in the waters of the Bay of Cadiz, for both avian and human consumption. The dunes, both moving and established, allow for the presence of a great botanical variety, such as marram grass, spiny thrift and broom; while in its surroundings there are pine forests, like those of Algaida and Los Toruños, where the stone pine shelters an undergrowth able to withstand the winds and salty atmosphere. These forests are a sanctuary for birds such as blackbirds, robins, owls and kestrels, as well as for chameleons, amphibians and mammals like the European hedgehog and the dormouse.
The sea and wind have created the perfect setting to enjoy a boat ride around the bay or fly over the waves practising windsurfing on its many good beaches. You can enter the depths of the sea by practising snorkelling or by kayaking. Discover the rich natural and ethnographic heritage of the area. In the 18th century, there were up to 143 salt mines and a good number of tide mills.
From the visitor's centre at San Fernando, there are seven trails of varying length, for walkers and cyclists, that take you into the marismas. There are also access points at El Trocadero.
The Visitor Centre of the Bay of Cadiz Nature Reserve is in San Fernando (Cadiz). The recently built facilities, a model with regards to sustainability, are located at the Salina of La Leocadia, opposite the Camposoto Beach. The ideal place for a visit to this Nature Reserve, as its facilities offer you diverse information on the area and the activities possible there.