Las Machotas Nature · Zarzalejo, Sierra Oeste, Madrid A twin granite summit on the southern slope of the sierra de Guadarrama, separated from its main range by faults, between the municipalities of Zarzalejo, El Escorial and San Lorenzo de El Escorial. The Machota Alta, 1,464 metres high and known as the Pico del Fraile, and the Machota Baja, 1,404 metres high and with a more rugged relief, result from an ancient plutonic intrusion whose differential erosion has left abundant granite boulders and boulder fields, such as la Bola, el Badajo or el Gigante Mudo. Oak and chestnut woods grow on its slopes —some classified as monumental trees— and, higher up, juniper stands and broom scrub. They form part of the Bien de Interés Cultural (Spain's highest level of heritage protection) named El Escorial: Monasterio, Sitio y Entorno Natural y Cultural, and are reached from Zarzalejo. Photo: Esetena (CC BY-SA 3.0) What to see and do in Zarzalejo