Leaving the car in the clearing near the Comba fountain, start climbing, following the Ru horse trail sign, along the dirt track that touches the Pied du Plan chalets and with a few hairpin bends climbs the sunny slope of the high Allein hill. Just beyond Baravex Meiten, the trail enters the forest momentarily, then arrives at Baravex damon 1905 m, in the vicinity of the Dortoir Baravex, a private hut open in the summer and run by the alpine group.Here you meet the signs for trail 24A on the right, leave the main dirt road to enter the pine forest, finding the Ru bridleway a little further on. Continue to the right along the pleasant road that ends at the Arp de Praz, where you also meet the Ru d'Allein. You continue upstream of the alpine pasture, passing a metal bridge under which the Ru flows, at first hidden under the track and then a little further on the water flows visible parallel to the beautiful path always on a gentle slope; you pass near a small waterfall and then arrive at the comba of Champillon, at Plan du Débat 2076 m (fountain) where you meet the paved road coming from Doues.From here on, the frequentation of the trail will increase, you will pass the small pond with the picnic area and always flanking the Ru you will find the signs for trail no.9 for the Champillon Refuge.Following the watercourse you pass by the Our Lady of the Snows chapel, then the trail intercepts the dirt service road to the refuge, which should be followed for a short distance to the Pessinoille 2150 m alp, where the trail continues at the edge into the larch forest on the left and then rejoins the dirt road in the clearing above with the large Tsa de Champillon 2297 m alpine pasture.From here you can now see the hut located on the grassy knoll not far away, and you reach it by continuing along the wide dirt track, with some short steeper sections, until you reach the beautiful Champillon hut near one of the many streams that furrow the slopes. From the hut's scenic terrace, where a restorative break can be taken, there is an expansive view of all the high peaks overlooking the Conca di By, from Mont Gelè to the Grand Combin.The return takes place along the same route as the ascent, with the possibility of admiring the views that on the outward journey had left behind, especially from Baravex one finds oneself on a real panoramic balcony with views of all the glaciers of the Rutor group and the Valley of the Great St. Bernard, as well as the basin of Aosta.