HU-631 is a challenging high mountain road located in the Ordesa y Monte Perdido National Park, in the Sobrarbe region, province of Huesca, Spain. During some periods of the year, the road is just one direction. It still remains an adrenaline-pumping journey and is definitely not for the faint of lungs, heart, or legs. It is narrow, so keep the speed down and be ready to move over and make room for oncoming vehicles.
The road is 34.3km long. It's asphalted but in very poor conditions, especially after rains. It's pretty slippery. The road is in dreadful condition and requires strong nerves to negotiate it. It’s certainly breathtaking and it has a fearsome reputation.
The drive is pretty steep. It links Escalona, a small town in the municipality of Puértolas, province of Huesca, at an elevation of 613 meters above the sea level, and Sarvisé, at 893masl. Its highest elevation is 1.360m above the sea level. This road has humbled many egos. It’s not for the sissies and shouldn’t be attempted by novice drivers. Some sections of the road are extremely narrow.
During some periods of the year, the road is just one direction. It follows the river Bellos and runs through the Valle de Añisclo, los Sestrales and Desfiladero de las Cambras. There are some narrow sections -scarcely wide enough for two cars- where if two vehicles have to pass each other, one might have to reverse for some kilometers of winding narrow road to get to a place wide enough to pass. It shouldn’t be attempted by those who don't know how to reverse.
The road is difficult and it’s a nightmare in the wet or dark (or both). The experience of using this road is very impressive. The most stunning part is along the Cañon de Añisclo. Añisclo is an awesome canyon. From the bottom of the canyon, looking upwards, you may feel dizzy, overwhelmed by its high walls. The road includes several unlit tunnels. This road tests the skill, and courage, of any driver. It’s definitely not for anyone suffering from vertigo or a fear of landslides. There is little room for error on this road.