Lac des Sirènes

Lac des Sirènes is a small mountain lake sitting at 2,390 m above sea level in the commune of Orcières (Hautes-Alpes), in the Champsaur valley within the Écrins massif. It lies roughly 4 km north of the Orcières-Merlette ski resort and is one of several lakes scattered across the high pastures above Merlette that draw hikers during the summer season.

Where exactly is the lake located?

Lac des Sirènes sits in the upper part of the valley, above the tree line, surrounded by typical Champsaur alpine vegetation. The surrounding bedrock is made of grès du Champsaur, a coarse-grained flysch sandstone in which sandstone layers alternate with clayey schists. This rock formed during the Priabonian stage of the Upper Eocene, roughly 34 to 38 million years ago. Right at the shoreline, clayey schists dominate, giving the banks a darker, distinctive tone.

What fish live in Lac des Sirènes?

The lake holds Arctic char (Salvelinus alpinus), a species considered native to this water body and whose population is periodically supported through restocking. This makes the lake a destination for anglers visiting the Hautes-Alpes.

How do you get to Lac des Sirènes?

The most common starting point is the hamlet of Merlette, from where the round-trip hike takes about 3 hours 30 minutes with roughly 590 m of cumulative elevation gain. The route is rated easy and doesn't require specialized mountain experience. An alternative is to start from the highest car park at Orcières-Merlette (around 1,870 m), from where part of the climb can be covered using the télémix chairlift, cutting down the walking time.

What else is worth seeing nearby?

From Lac des Sirènes, the trail continues past Lac Long toward Grand Lac des Estaris, sitting at 2,558 m — one of the more popular hikes in the Champsaur area, crossing high alpine meadows and pastures. The valley is overlooked by several peaks, including Mourre Froid (2,993 m), Roche Brune (2,956 m), Roc Diolon (3,071 m) and Grande Autane (2,782 m), visible from many points along the route. Near Grand Lac des Estaris lies a protected cirque where additional restrictions apply to dogs.

Frequently asked questions

At what altitude is Lac des Sirènes? The lake sits at 2,390 m above sea level, in the commune of Orcières.

How long does it take to reach the lake? From the hamlet of Merlette, the round trip takes about 3 hours 30 minutes, with around 590 m of elevation gain.

Can you fish in the lake? Yes, Lac des Sirènes holds Arctic char, and the population is supported through periodic restocking.

Is the trail difficult? The section leading to Lac des Sirènes is rated easy and suitable for hikers with average fitness, and the walking time can be shortened using the chairlift from Orcières-Merlette.

Can this hike be combined with other lakes? Yes — the trail continues past Lac Long to Grand Lac des Estaris, forming a loop that is popular with visitors to the Écrins massif.