We started the route from the Puerto del León car park on its Madrid side. We go first to La Sevillana where we find a recital of bunkers, trenches, cisterns and remains of military barracks for troops and commanders. All this a short distance from the port and around 1,556 meters above sea level of La Sevillana.
We go back down to Puerto del León and go up the track, initially paved, also seeing some bunker and military buildings in ruins. In Las Hondillas we turn right to go up following the GR-10 markings to the Cerro de la Gamonosa where the remains of a military observatory camouflaged among the rocks are in good condition.
We continue descending a bit to Collado de la Gasca to make the last and strongest climb of the day, following the GR-10, towards Cabeza Lijar where, below its top there is a bunker dwelling.
Then we go down, following the GR-10, towards Collado de la Mina or de la Cierva. At that point we begin the return in a more comfortable way along the track that returns us to Puerto de León.
Max elevation: 1815 m
Total climbing: 717 m
Total time: 04:01:26