Set at 2,063 metres in the Sixt-Passy nature preserve, this glacial lake is one of the finest destinations in the area for a long day hike from the village. The surface covers 11.6 hectares and the water stays cold enough in summer that swimming is for the hardy only; the setting — surrounded by limestone ridges with the Pointe d'Anterne looming above — more than compensates. Most walkers reach the lake via the Refuge Alfred Wills, adding another hour or so above the refuge. From the Col d'Anterne above the lake you can descend into the Chamonix valley, making a two-day crossing possible with a night at the refuge.