Manzanares (river) protected as the "Parque Regional de la Cuenca Alta del Manzanares", a nature reserve which is recognised as a biosphere reserve by UNESCO. The Manzanares flows in a south-eastern direction from its source, and passes through the medieval town of Manzanares el Real where it is dammed to form the Santillana reservoir, one of the most important water supplies for the capital. The river then takes a southern direction and enters the Monte del Pardo, an ecologically valuable area on the edge of Madrid. The river is canalised where it passes through the built-up areas of the city. As at
Soto del Real it is protected inside the Parque Regional de la Cuenca Alta del Manzanares. It borders with Manzanares el Real on the West, Miraflores de la Sierra on the East, Colmenar Viejo on the South, and Rascafría on the North. Soto del Real encompasses a variety of terrains: mountain tops, slopes, and the Manzanares-Guadalix tectonic pit. The urban nucleus is inside the pit, going through the Mediano, Chozas and Matarrubias streams, which flow into the Santillana reservoir, so they are tributaries of the Manzanares river. Geologically speaking, it is divided into the Mountain range, where there is a predominance of Gneiss