GR11 (La Senda Pirenaica)

The GR11 — La Senda Pirenaica — is the Spanish-side traverse of the Pyrenees, 850 km from Cabo Higer on the Atlantic just east of San Sebastián to Cap de Creus on the Mediterranean above the Costa Brava. It runs roughly parallel to France's GR10 about 20–50 km to the south, generally staying higher and wilder, with bigger daily climbs and longer sections between resupply villages. Most thru-hikers take 40–50 days; the trail divides into 47 official stages of 7–31 km.

The route walks west-to-east through six provinces — Navarra, Aragón, Catalonia, and the autonomous regions in between — with each transition bringing a noticeable landscape shift. Basque Navarra opens with green hills and ferns; Aragonese Hecho and Ordesa valleys give the trail its high-mountain core (Monte Perdido's 3,355 m glaciated face, the Bujaruelo pastures, the Aigüestortes lake plateau); Catalonia's eastern stretches descend through wine country and Mediterranean scrub to the rocky cape itself. The Aigüestortes National Park section is the trail's headline week, with refugios spaced at one-day intervals around the Encantats peaks.

Walking season is mid-July to early September — outside that, the high refugios close and the upper passes hold snow. The trail is well-marked with red-and-white GR stripes but less developed than the GR10: more cross-country navigation, more nights at unstaffed mountain shelters, and Spanish-only signage in many villages. Refugios cost €15–25 per bed without food; resupply is easier than the wilderness profile suggests because most stages end in a village. Cicerone's "Trekking the GR11 Trail" (Brian Johnson) is the English-language reference. Pyrenean weather changes fast — pack proper rain gear and a warm layer even in August.