A little road join Sallent de Gállego with the reservoir of La Sarra where we leave the car (3.5 km).
Approach to Mountain Hut of Respomuso from La Sarra (2h 30min): Faxas's bridge we will pass the reservoir up to a way that enters the valley towards the ibón (lake) and mountain hut of Respomuso for a beautiful forest of beeches across the narrow Paso (pass) de l'Onso. We will come to a level zone (Llano Cheto, 40-50 min) to continue for new slope up to the most top part of the valley. On the west we will see the wall of the prey of Respomuso's dam where we will go. After leaving behind the house of the engineer and hermitage of Ntra Sra de las Nieves (St Mary of the Snow) we will come to the refuge of mountain.
From this mountain hut is possible to climb greats mountains like Balaitous (3151m), Frondella (3071m), Cristales (2886m), Gran Facha (3005m), Pallas (2974m), Arriel (2825m), Cambales (2965m),...
For the people who sleeps in Respomuso's mountain hut, generally to ascend to the Balaitous, Gran Facha,..., if they have of more days also they can do an hike to the Picos del Infierno. This route is not the habitual one to ascend to these peaks (see Pondiellos or Tebarray's routes) because is longer (5-6h climb+6h descent).
From Respomuso (2150m) bordering on the dam for the tail and following the marks of red and white painting of GR11 we continue for the valley up to the ibón of Llena Cantal (3h45min,2430m) under the peak of the same name. Between the peaks of Piedrafita (2915m) and Tebarray (2915m) we arrive to Col of Tebarray with the ibon (lake) of Tebarray. In this climb to Col of Tebarray is possible the presence of snow. We leave the marks of GR11 and we go to Col of the Infiernos to the right. This point is the same of the final of route of Tebarray for reach the Western infierno and across "la marmolera" the Central Infierno.
Water clothes in summer (storms are frequents). Ice axe and crampons in winter (very dangerous).