They are one of the most prominent areas of permanent continental freshwater upwelling. Between orchards and rice fields, they are between the localities of Amposta and Sant Carles de la Ràpita. Surrounded by natural channels, you can see turtles, frogs and characteristic birds of this area such as the capuchin warbler and the bee-eater. Eucalyptus forests and the presence of water lilies are also distinctive of this area declared a fishing refuge and local hunting reserve.