The Nature Reserve of the Endorreic Complex of Lebrija-Las Cabezas, together with that of Espera, are the last redoubt of a great lagoon system that ran through the entire countryside between Seville and Cadiz. Human activity has gradually reduced the wetland to the lagoons of La Cigarrera, Galiana, Peña, Pilón, Taraje (the only permanent one) and Charroao, known as Bujadillo or Herradura.
The Peñón de Zaframagón is located between the towns of Olvera (Cádiz) and Coripe (Seville), in the last foothills of the Grazalema mountain range, where the Sub-Baetic range borders the River Guadalquivir depression.
The Brazo del Este was one of the two branches into which the lower section of the River Guadalquivir was divided. In the marshland plain, The River Guadalquivir splits into several branches when it reaches the marsh plains. The three largest branches were the Brazo del Este, Enmedio, which is the current watercourse, and Torre, also known as the Northwest Branch.
From a geological point of view, the Malpasillo reservoir is part of the Sub-Baetic unit of the Betic mountain ranges.
Like the rest of the wetlands located in the strip between the Baetic mountain range and the Guadalquivir Depression, this wetland area consists of three shallow lagoons: Zarracatín, Arjona and Alcaparrosa. Its seasonal nature makes it dependent on dependent of direct rainfall recharge; therefore, it is usually dry in the summer or during persistent drought.
This natural enclave is one of the most important in Europe. It is an extremely important wintering, migratory and breeding area for many bird species. Furthermore, it is one of the last havens for endangered wildlife species such as the Imperial eagle or the Iberian lynx.
The Laguna del Gosque is an endorheic and seasonal wetland. It is located on flat terrain, in an area of undulating relief and gentle hills, near the Sierra de los Caballos, in the south of the province of Seville.