The river is notable for having some of the only marshland on the Costa del Sol. This marsh is protected by a 27 hectares (67 acres)[1] nature preserve. There are several towns and communities near its mouth, Pueblonuevo de Guadiaro, Guadiaro, Torreguadiaro, Sotogrande, San Enrique, and Venta Nueva, all located within the San Roque municipality.