The Sierra de Guadarrama (Guadarrama Mountains) is a mountain range forming the main eastern section of the Sistema Central, the system of mountain ranges along the centre of the Iberian Peninsula. It is in Spain, between the systems Sierra de Gredos in the province of Ávila, and Sierra de Ayllón in the province of Guadalajara.
The range runs southwest–northeast, extending from the province of Ávila in the southwest, through the Community of Madrid, to the province of Segovia in the northeast. The range measures approximately 80 kilometres (50 mi) in length. Its highest peak is Peñalara, 2,428 metres (7,966 ft) in elevation.
