Middle of the Lozoya valley
Horcajo de la Sierra
The municipality is formed by two small towns, Horcajo de la Sierra and Aoslos, marked by the livestock activity in its history, in its architecture and urban development. Low buildings are still preserved, of rustic stone masonry which were primitive pens and shelter for shepherds. Dwellings are distributed in the urban setting with ancient pajares, corrals and stables. In the surroundings of the town and along the Madarquillos River, irrigation land was distributed for orchard and fruit crops. There is also an oak dehesa Boyal or common land for cattle pasture.
One of the first mentions of this town dates back to the 14th century, in the "Book of the Mountain". Apparently, the village of Horcajo was built around a Tower-Strong, which was transformed into a bell tower, next to which the church of St. Peter in Cathedra was built, 15th-century Gothic style.
Some isolated agricultural units and rural dwellings are of interest in their rural architecture (s. 18th to 20th).