GR10 Transpyrénéen

The GR10 is France's answer to the Appalachian Trail — a trail that runs the full length of a mountain range from ocean to ocean, in this case from the Atlantic at Hendaye west of Bayonne to the Mediterranean at Banyuls-sur-Mer east of Perpignan. The route stays on the French side of the border, threading through the ski towns, shepherd villages, and genuinely remote sections of the Pyrénées that walkers have been traversing since the trail was marked in the 1970s.

The total elevation gain — approximately 50,000m across 900km — is greater than ascending and descending Everest from sea level five times. This is a direct consequence of the Pyrénéan topography: the range is deeply dissected by north-flowing rivers, meaning the GR10 descends from ridge to valley floor and climbs back to ridge in a repeating cycle that accumulates gain rapidly even when the peaks in view aren't particularly high.

The western section (Basque Country and Béarn) is green, wet, and technically demanding in a low-altitude way. The Basque hills rise steeply from the Atlantic coast, and the ridge sections above Larrau and Sainte-Engrâce are exposed to the Atlantic weather systems that push inland without obstruction. Brown bears have been reintroduced to this section of the Pyrénées and are present in small but growing numbers — encounters are rare but documented.

The central section through the Hautes-Pyrénées is the highest and most dramatic. The section around the Cirque de Gavarnie — a 1700m natural amphitheatre with the Grande Cascade visible from 10km away — is one of the great landscape set pieces of European trekking. The Balaitous and Néouvielle wilderness areas north of the border have no hut access for multi-day sections, requiring full camping self-sufficiency.

The Ariège and eastern sections are lower, drier, and faster. The Catalan Pyrénées around Ax-les-Thermes have an almost Mediterranean character in summer — dry scrub, wild thyme, and herds of horses on the plateau.

Most trail runners take 18-25 days. The season window is strict — snow on the high passes into July and back by October.