Collado de Sahún is a high mountain pass at an elevation of 1.998m (6,555ft) above the sea level, located in the province of Huesca, Aragon, Spain. The road to reach the summit is mostly gravel, with some concrete sections.
The road to the summit is called Pista de Chía. It's a challenging high mountain road. It is mostly unsurfaced, but smooth enough track for cars. This epic pass, which links the town of Castejón de Sos to the Valle de Gistaín, can be approached from either side. The official pass is at 1.998m and overlooks the spectacular Barranco Llisat, but the actual highest point on the road is a little above that, at 2.020m. There are 2 routes to reach the summit. Starting from San Pedro Tabarnes, the ascent is 16.5 km long. Over this distance, the elevation gain is 881 meters. The average percentage is 5.3 %. And starting from Salinas, the ascent is 21.3 km long. Over this distance, the elevation gain is 924 meters. The average percentage is 4.3 %. This road can be closed anytime when the access is not cleared of snow. Large sections of the west side are facing north, so keeping the road open in winter and maintenance works would be costly.
Pic: José Petuya