The route of Alfonso Onceno between the town of Guadalupe and the village of Navezuelas is one of the best-known and most popular in the Geopark; with this crossing the route continues until it links up with the Camino de los Jerónimos (Hieronymites’ Trail) (GR 118) on a level with La Avellaneda. With a total length of 58.3 km the route is best divided into at least three stages.
It is a demanding itinerary owing to its length and the differences in height; the altitude ranges from the 400 m at the start to the 1237 m of the Collado de la Arena. The route begins 500 m northeast of La Avellaneda and makes for Fresnedoso de Ibor crossing the River Ibor itself. From this village we continue towards Robledollano crossing the Sierra de la Madera via the Collado de Carboneros to continue as far as Roturas on the Navazos Trail. From here the route climbs to the Sierra de la Ortijuela on the trail of the same name and via its sunny side on hillside debris of huge stones scattered with cork oaks (Quercus suber) and ascends the Valley of Santa Lucía to make for Navezuelas among cultivations of chestnut trees (Castanea sativa) once past the Collado de las Carretas. Before the latter we come to the link with the Cabañas del Castillo-Ortijuela route (PR-CC 144) which allows us to reach this pretty village to spend the night and visit the remains of its fortress. It is in Navezuelas where the traditional route of Alfonso Onceno begins (with the most mountainous section of the crossing) on the bridle path which connects this village to Guadalupe via the Sierra de las Acebadillas and the impressive Valley of the River Viejas on the banks of which the Portuguese laurel (Prunus lusitanica) abounds. Finally we come to the Collado de las Arenas from where we descend among Pyrenean oaks (Quercus pyrenaica) first to El Humilladero and then to end the route at Guadalupe.
On the way we can observe griffon vultures (Gyps fulvus) and golden eagles (Aquila chrysaetos) and on the peaks birds such as the black wheatear (Oenanthe leucura) and the rock thrush (Monticola solitarius).