Route of great ethnographic value that takes us to travel part of one of the most important glens of the peninsular center. The transhumance, one of the activities with more historical significance in the Sierra Norte, It translates into this route where entered and came out each year thousands of Heads of cattle to graze on the slopes, hills and harbours of the Sierra Norte during the summer.

With the possibility to start at Bustarviejo or Buitrago, the route described below got its start in Buitrago del Lozoya, Historic-artistic and cultural, where stands the medieval wall that was declared a national monument.

The route starts in direction to the reservoir of Riosequillo, next to the Peralta College, Once crossed the highway, turn towards the South. The path between holm oaks and oaks gently gains height as we head to El Cuadrón which leaves us beautiful images of the swamp. Last of the Cuadrón population, We won the Portachuelo pass, and we look out to the Sierra de la Cabrera, the road skirts the slopes of Peña Negra, and we pass next to a former postwar criminal.

We reach one of the places with more tradition in the path between the Sierra de la Cabrera and Peña Negra, the pass of the half bushel. At this point is charged to the shepherds driving flocks a portazgo or tax into the lands of the Manor of Buitrago. Which consisted in half bushel (Measure of capacity) wheat.

From here the road llanea faldeando the slopes of Peña Negra and the Mondalindo up to the pretty hill town of Bustarviejo.