Consists of 24 wetlands. It is of great national and international importance because of its biological diversity. Thirty-nine plant species are identified, 25 of them on the IUCN Red List, and 162 bird species including the horned screamer (Anhima cornuta) whose populations are found only in Sonso and in the Cienaga del Conchal, also in Colombia. The Site presents a high level of endemism with five endemic fish species; the boquiancha (Genycharax tarpon); the roño (Callichthys fabricioi); the micudo (Pimelodella macrocephala); and two sardines (Hyphessobrycon poecilioides and (Gephyrocharax caucanus). The complex has outstanding ecological values due to its landscape, its biodiversity, and its considerable tourism and recreational potential. It is a source of food and water for the locals, while also providing educational opportunities through an environmental education and research centre. Threats include the growth of the population and the increase in the extent of land used for agriculture, especially sugar cane cultivation.