Lac d'Arlet

Lac d'Arlet is a glacial mountain lake in the commune of Borce, in the Pyrénées-Atlantiques department of France, sitting at nearly 2,000 metres above sea level in the upper Aspe valley, inside the Pyrenees National Park, close to the Spanish border.

Where exactly is the lake?

The lake lies at the foot of the Pic d'Arlet, in the high section of the Aspe valley. It's a modest body of water, covering roughly 2.7 hectares and reaching a maximum depth of about 7 metres — dimensions typical of a small lake carved out by glacial action rather than by a river.

How do you get there?

Reaching Lac d'Arlet means walking, on a route covering roughly 18 kilometres round trip. The starting point is Maison Lamourane, where the paved road out of Borce comes to an end. From there, the trail crosses the pastures of the Vallon de l'Aubise before climbing to the lakeshore. With close to 1,000 metres of elevation gain and a walking time counted in hours rather than minutes, this is a demanding outing best suited to hikers with some mountain experience.

Because the lake sits within the core zone of the Pyrenees National Park, painted trail markers are not allowed there, so part of the route relies on directional signposts instead of the usual paint blazes. Along the way, the landscape shifts repeatedly: forest, then open grazing land, then stretches beneath steep rock faces.

Is there somewhere to stay overnight?

Yes. The Refuge d'Arlet stands right on the lake's edge and is the only staffed mountain hut in the entire Aspe valley. It's guarded and run through the summer season by Pyrenees National Park staff, which makes it possible to plan longer, multi-day itineraries in this stretch of the range near the French-Spanish border.

Who is this hike for?

Given the distance, the elevation gain, and the partly unmarked trail, the walk to Lac d'Arlet suits hikers who are reasonably fit and looking for a quieter, wilder corner of the western Pyrenees. The payoff is a lake sitting almost two thousand metres up, framed by the high-mountain scenery typical of this part of the range.

FAQ

Where is Lac d'Arlet located? In the commune of Borce, Pyrénées-Atlantiques department, in the Aspe valley of the French Pyrenees, near the border with Spain.

How high up is the lake? At an altitude of close to 2,000 metres above sea level.

How long is the trail to Lac d'Arlet? The round trip covers about 18 kilometres, starting from Maison Lamourane at the edge of Borce.

Is there a refuge at the lake? Yes — the Refuge d'Arlet, the only staffed hut in the Aspe valley, open and guarded during summer.

Is the trail waymarked? Only partly. Painted markers are banned in the park's core zone, so signposts guide hikers instead of the usual paint blazes.