Reservoir of la Jarosa Nature · Guadarrama, Cuenca del Guadarrama, Madrid The smallest of the reservoirs in the sierra de Guadarrama, with 7.2 cubic hectometres and 55 hectares of water surface, located in the valley of La Jarosa, in the municipality of Guadarrama. Besides the reservoir, the name La Jarosa also refers to the meadows on its banks, which total 93 hectares, several recreation areas and the extensive reforested pine woods amid which it lies, where the hermitages of Nuestra Señora de la Jarosa and del Altar Mayor stand. Included in the Catálogo de Embalses y Zonas Húmedas de la Comunidad de Madrid and in the Guadarrama National Park, its lower area forms part of the park's socio-economic interest zone, while the upper part, next to the puerto de Guadarrama, lies within the Protection Zone. Photo: Cruccone (CC BY 3.0) What to see and do in Guadarrama