Sierra de Guadarrama

The Sierra de Guadarrama is a mountain range forming the main eastern section of the Sistema Central, the system of mountain ranges at the centre of the Iberian Peninsula. It is located between the Sierra de Gredos in the province of Ávila, and Sierra de Ayllón in the province of Guadalajara. The range runs southwest - northeast, extending into the province of Madrid to the south, and towards the provinces of Ávila and Segovia to the north. The chain as a whole measures approximately 80 km in length, with its highest peak, Peñalara, reaching 2,428 m above sea level (7,965 ft).

The vegetation of the mountain range is characterized by an abundance of pine forests and copses of oak and Holm oak in its lower slopes, while the montane grasslands and pastures around the summits are fringed by juniper and Spanish Broom shrubs. The mountains abound with a variety of wildlife such as Spanish ibex, roe deer, fallow deer, wild boar, badger, various types of weasel, European wild cat, fox and hare. The area is also rich in birdlife including birds of prey such as the Spanish Imperial Eagle and the Eurasian Black Vulture.

The mountain range's proximity to Madrid means it can get crowded. The area is today crossed by numerous passes and railway routes and sustains a highly developed tourism infrastructure, coupled with provisions for various mountain sports; this poses a threat to the fragile environment of the mountains.