Doñana National Park in Andalusia occupies the right bank of the Guadalquivir river at its estuary on the Atlantic Ocean. It is notable for the great diversity of its biotopes, especially lagoons, marshlands, fixed and mobile dunes, scrub woodland and maquis. It is one of the largest heronries in the Mediterranean region and is the wintering site for more than 500,000 water fowl each year.
Valdeserrillas has been set up as an animal reserve and is supported by the Municipality of Benageber. The current size of the reserve is 365 hectares. The amount of hectares is bound to increase in this and following years. Valdeserrillas is also in the final stage of acquiring UNESCO status.