We start this route, like so many others, in the parking lot of the port of Navacerrada. We go up the street that leads to the Bola del Mundo chairlift cabin and turn to the right, after passing through the Red Cross and the Civil Guard barracks, to continue along the well-known path of other routes, what is the path of the Cabrillas, along which we will go up until we join the concrete track and, without leaving her, We will reach the television repeater building, which we will border on the right and find the geodesic vertex, after having traveled 3.5km in one hour.

We continue skirting the building, until you find a path that descends to the right until you pass near some ruins of an old shelter. This descending path takes us to the Piornal hill (5 km in an hour and a half from the start) where we will see a rain gauge, near which we will pass to begin a climb through a quarry that in about half an hour will allow us to reach the top of Maliciosa. From here we have a magnificent panoramic view of a large part of the Madrid mountains.: we see the swamp and the town of Navacerrada, We look into the Barranca area, from where we will go up another time, we will be able to see the Manzanares el Real reservoir and the town, the Helm and the Tolmo of La Pedriza, and even on a clear day our sight can reach Madrid.

It is best to go up with a good map to be able to locate everything we can see.. We will take the return route along the same route that helped us get here.. As a variant we can use the entire concrete track, instead of deviating to the path of the Cabrillas.

In any case, It is a route that has the greatest difficulty at the beginning when we must overcome the difference in altitude of about 400 meters between the port of Navacerrada and the geodesic vertex of the Bola del Mundo.