This freshwater lake is home to a large number of water birds. Along with the Marismas del Odiel, Marismas del Río Piedras and Flecha del Rompido Natural Areas , it forms a network of wetlands that is fundamental for the survival of birds that migrate to the Iberian Peninsula each year.

The lake has its origins in the gradual accumulation of sand from mobile dune fronts. The blockage this cased gradually stopped the flow of water from the small streams in the area out into the sea. Its evolution is closely linked to the movements of areas of sand along the coast, on account of their proximity.

From the El Portil viewpoint, at the beginning of the Laguna del Portil trail that runs around the perimetre of the lake, there is an excellent panoramic view of the area. You can see the surrounding vegetation, comprised mainly of coco grass, bulrushes and reeds. There is an abundance of wildlife to be found on its waters. You can see the interesting courting of crested grebes and the long, sharp snort-like sound of the little grebe. This bird dives underwater sensing danger and can swim several metres underneath the surface. It is also common to see gulls that fish out at sea and come to these waters to wash the salt off their plumage.

As a stop off for migratory birds, this is an ideal place to spot rare species in summer and autumn, such as the garganey. Following the trail you can see how the vegetation changes. As the ground becomes more solid there is Phoenician juniper, mastic, white broom and replanted rock pine.

A perfect place for a rest is the La Norieta Periurban Park, next to the reserve, where you can also enjoy the countryside. You can also visit excellent beaches such as La Bota or El Portil, with a wide range of leisure activities and water sports. Furthermore, close by is Cartaya, which has a wealth of historic and artistic heritage. Examples are Los Zúñigas Castle, a fortress tower built in the 15th century and designated National Monument, the Andalusian Baroque style Consolación Chapel and the Dehesa and Mogaya water fountains.