This route is a hiking loop that starts and ends in Peñarroyas. At first the route is parallel to the GR-262 in the direction of Obón, several points of geological interest with thematic interpretative feet (faults, polygonal drying traces, ripples …) shape a cobbled route from the town to reach the viewpoint of Portillo., The pass that opens up at the top of the Peñas Royas.
Then we take the path to the left, old path to La Hoz de la Vieja and where also runs a variant of the GR (known by the name of return to the pigeon lofts) that brings us to the ravine of the Val. After a short time we will leave the variant that will be on our right towards the Martín river, and we will continue on the path until we reach the corrals of the Umbrías.
Shortly after we will reach the ravine of the cingla and the landscape changes again. An outcrop of red sandstone where erosive agents have formed a canyoning of the ravine known as the Pelegrina gully, showing a channel with small and charming waterfalls and pools or badinas.
After ascending along the same riverbed, leaving behind the outcrops of the rodeno, the landscape comes into contact with outcrops of the Carboniferous. The colors of the grayish slabs contrast now, highlighting a series of angular folds lying on the terrace of the same riverbed. There we will leave the ravine on its right bank, ascending a steep path to the Pilón corral, where we will connect with the traditional path of Armillas. The nickname “del Pilón” is given by the remains of an old peirón or term cross, made with blocks of ródeno in its base that are still observable collapsed. Some blocks preserve engravings of a cross. It is the highest point of the route with 1,021 meters above sea level.
From here we will begin a descent along the aforementioned path that runs parallel to the rocky cinglera of Peñas Royas, which crowns the slope, and from which numerous blocks have broken off that we will find along the path.
Some of these blocks preserve rock engravings, predominantly Christianization crosses, which probably served to sacralize this path that must have been very busy, either as a route to the salt mines -salt was a very precious commodity in past centuries- in the town of Armillas, and that would give its name to the path, either for its religious facet of pilgrimage or pilgrimages to the hermitage of the Virgen de la Aliaga in Cortes de Aragón or to the hermitage of San Antón in Armillas, a small town with four hermitages (that of San Antón, that of San Ramón, La Virgen del Pilar and La Purísima).
Halfway up the slope we can also observe some outcrops of subvocanic rocks that outcrop in the Abellar ravine, which we can identify by their yellowish ochre color, and whose origin was at the end of the Carboniferous, when the subcortical magma cooled in the subsoil, in areas close to the surface, giving rise to these unique rocks. In this section of the trail we will find a shelter -known as the lodge-, which can serve as a refuge if there are storms. Shortly after we will reach Peñarroyas again.
