Laguna de la Nava de Fuentes. 24/10/2002; Castilla y León; 326 ha; 42°0412N 004°4500W; Natura 2000 (SPA, SCI). Originally a steppe lake covering more than 2,000 ha in the north of Spain, after years of draining the lake had disappeared by 1968; the current shallow wetland is the result of a successful restoration project which began in 1990. The hydrological levels are artificially regulated and during the dry periods part of the lake area is grazed by sheep. The wetland plays a very important role as resting place for ducks and shorebirds during migration, reaching concentrations of more than 20,000 individuals, and more than 200,000 greylag geese Anser anser as well as over 10,000 mallards Anas platyrhynchos winter in the site. Several endangered species such as the Great Bittern Botaurus stellaris and Aquatic Warbler Acrocephalus paludicola can also be found there. Some of the threats which might affect the ecological characteristics are mainly processes of eutrophication and pollution caused by agricultural activities. In recent years several ornithological, limnological and botanical studies have been carried out, and a new management plan for the site is in preparation. Ramsar site no. 1260. Most recent RIS information: 2012.