Col du Soulor, Mountain pass in Arbéost and Arrens-Marsous, France

The col du Soulor is a mountain pass in the French Pyrenees, linking the Ouzom and Arens valleys at roughly 4,800 feet (about 1,470 m) above sea level. The road crossing it is paved but narrow and winding, with rocky slopes on one side and open views over the valleys on the other.

The pass lies on the route départementale D 918, the former Route Thermale des Pyrénées linking Argelès-Gazost with Laruns via the Col d'Aubisque, 10 km west. The D 126 branches off the col and descends past the Cirque du Litor toward Asson. The Tour de France first crossed the col in 1910 and returned in the 12th stage of 2025 as a category 1 climb; it has been a categorized climb on 14 occasions, including 1982 as hors catégorie.

The col du Soulor has been part of the Tour de France since 1910, and cycling fans still come here to ride the same road the race has used for over a century. The steepest sections just before the top give a clear sense of why this climb has a lasting reputation among riders.

The pass is generally open from late spring through early fall, but snow and ice can close the road during winter months. Before heading up, it is worth checking conditions, as the road is narrow and can become difficult quickly when the weather turns.

In Pyrenean toponymy, soulor designates slopes exposed to the full sun of the day, to the east where the sun rises; the Gascon form is eth soulor. The pass is also crossed by the GR101 long-distance footpath, and in summer its winter ski trails become walking and mountain-bike routes.