The Castillo de Acher (Castle of Acher) is one of the most curious mountains of the Pyrenees due to his characteristic form of syncline hung that makes alike it to an impregnable fortress (of there his name of castle).
Agreed, the name of "Castillo" is easily explained. The part of "Acher" is due to a nearby mountain pass placed to the southeast of the mountain, between the Castillo and Bisaurín. The name of the pass is "Achar de los Hombres" (Pass of the Men) and is supposedly named after some unknown men who might be the smugglers of the nearby villages, who would use this pass to get into France and back (thanks to eza for info).
Another names in some spanish maps: Monte Campanil, Castillo de Achert.
This mountain is located in the valley of Echo in the north of the province of Huesca near the impressive peak of Bisaurin (2670m) principal summit of this valley. Other summits in this valley: Peñaforca (2390m), Rincón de Alano (2353m), Lenito (2345m), Punta Agüerri (2249m), Puntal de Secus (2512m).
The trailhead of the normal route for this mountain is the Selva de Oza.
To arrive to valley of Echo:
-From Pamplona: Yesa-Puente la Reina de Jaca-Echo.
-From Zaragoza: Huesca-Jaca-Echo.
To arrive to Selva de Oza follow the road from the village of Echo (7 km).
No permits required. No parking pass.
It is suitable in summer to come early in the morning since it is a zone with great abundance of tourists and it's difficult to park the car later.
When To Climb
All the year.
In winter the final chimney that enters the castle (the only point of access to the top) can be frozen and be accessible only to experienced mountaineers .
Valley of Ansó / Echo Campings
-Camping of Zuriza. 2ªcat. 1000 places, open all year (974/370196).
-Camping Selva de Oza. 1ªcat. 360 places, open june to september (974/375168).
Mountain huts / refuges
-Refugio de Linza. (974/370112)-Ansó. 96 places.
-Refugio de Gabardito. (974/375358)-Echo.
-Refugio de Lizara (974/371473)-F.A.M.-Aragües del Puerto. 75 places.
-Ansó: Hostal Aisa * (974/370009).
-Echo: Hotel Lo Foratón II ** (974/375247).