Lagoon of los Patos Nature · San Agustín del Guadalix, Cuenca del Medio Jarama, Madrid Image of San Agustín del Guadalix, not of the place itself. A wetland in the district of San Agustín supporting a varied community of water birds and amphibians, and serving as a damp counterpoint to the nearby Moncalvillo pasture, public utility woodland number 132, kept up by grazing. Photo: Axel Schlaefer (CC BY-SA 3.0) What to see and do in San Agustín del Guadalix