This excursion begins in Alquézar, a little more than an hour from the Casas Ordesa rural holiday cottages. Once there, look for the trail close to the village square that leads out of town in the direction of the San Lucas ridge. The trail will at first be level, but later it will slope upwards to the top of the hill.
Once you have reached the top, it will be easy to identify the trail you must take to descend to the river as it is fenced off. This trail will lead you to the Villacantal bridge. Pass over the bridge and continue on until you reach a marked crossroads.
Turn left at the crossroads in the direction of the 'Abrigos de Arpan' and 'Fuente del Trucho'. A bit farther on, turn right and begin to climb up Lumos hill. Rather than following the trail that leads to the top of the hill, take the path to the left that runs down to the bottom of the ravine and then up again to the spring known as the Fuente del Trucho.
Once you have reached the Fuente del Trucho cave, continue on until you get to rocky clearing where you'll find two information panels. Arpán will be to your left and the paintings of Mallata will be straight ahead.
After you have visited Arpán, continue on to Mallata. A little further along, turn to the left and you will reach a trail. Turn left to enter that trail and follow it until you reach the paintings.
You must now return on the same path until you reach the crossroads in the trail leading up to Arpán. Continue straight ahead until you reach the roadway. A few metres further along, take the path that forks to the right in the direction of Asque but continues to run parallel to the roadway. This trail will cross the roadway and become a path that leads down to the crossroads at Asque flanked by a wall. From this point, follow the route until you reach Asque.
When you reach the church, take the signposted path that runs into a trail that descends to Fuentebaños. Cross the bridge in Fuentebaños and continue on another path that leads up to Alquezár.
When you reach a signposted intersection where the path becomes a gentle slope, turn right and continue on towards an old power station. Continue along the walkways, cross the dam and after following the walkways on the other side, turn left.
When you reach a series of wooden steps you will have reached the final stretch to Alquézar.