The hook
Catalonia's only national park: two hundred glacial lakes scattered across granite basins beneath the twin peaks of Els Encantats, linked by a hut-to-hut circuit, with a valley next door that faces north into France and speaks its own language.
01Why it's worth it
Aigüestortes i Estany de Sant Maurici is high Pyrenees at their best, "twisted waters" is what the name means, and the park is a maze of streams, waterfalls, pine and fir, and lake after lake at 2,000 metres and up. The classic way to take it is the Carros de Foc, a circuit linking nine mountain refuges that you can walk over four to seven days sleeping in huts, or sample as day hikes from Espot and Boí. The Vall d'Aran over the ridge is a genuine oddity: the only Spanish valley draining north to the Atlantic, historically cut off, with its own Occitan language (Aranese) and an unmatched cluster of Romanesque churches in the Vall de Boí, nine of them UNESCO-listed, slim stone bell towers standing in tiny mountain villages, their 12th-century frescoes among the finest in Europe. Add hot springs, and Baqueira's skiing in winter.
02How to experience it
Base in Espot or Boí and either day-hike to Sant Maurici and the Estany Llong, or book huts and walk a section of the Carros de Foc. Give a day to the Vall de Boí churches, ideally with the frescoes explained. Access to the park core is by shuttle taxi, not private car. July to September for reliable trail conditions; snow lingers late.
From the locals
Asked what foreign visitors overlook in Spain, the top answer heads straight for these mountains: "Get yourself up to Aigüestortes. You won't regret it," one wrote, adding that "the Pyrenees in general are beautiful and the criminally underrated Vall d'Aran is up the road." Others in the same thread push northern Spain generally, "if you like hiking then Picos de Europa in Asturias and Cantabria are a must."