Sierra de Ayllón
The Sierra de Ayllón is a mountain range in the east of the Central System (Sistema Central) that lies in three provinces: Guadalajara, Segovia and Madrid. On the southwest side it borders the Sierra Norte de Madrid and further towards the east lies the Sierra Norte de Guadalajara.
Special about this mountain range is that the valleys have the most southern beech forests of Europe: La Pedrosa, Montejo and the nature park Hayedo de Tejera Negra. In these mountains a number of rivers arise such as the Río Jarama, Río Sorbe, Río Jaramilla, Río Berbellido, Río Sonsaz and Río del Ermito.
This mountain range is a good altermative to - although farther away - visit from Madrid, because you see less people here and it has a different character than the Sierra de Madrid. It largely consists of slate and granite and to a lesser extent of gneiss, and it contains the last peaks of above 2,000 metres of the Central System, thanks to which it gives marvellous views both towards the mountains of Madrid and towards the lowland plain of Segovia.