Vallon lake in Bellevaux was created in 1943 by a huge landslip from a surrounding mountain which created a natural dam on Brevon river.
It is located in the mountains of french Chablais (NE par of Haute-Savoie department) and is surrounded by a beautiful mountain forest.
The mountain nicely reflected on the water is the Roc d'Enfer (Hell's Rock) and has an elevation of about 2 200m.
I spent the afternoon yesterday hiking around the lake under an amazing blue sky. I made a few images although it was not my favorite light but i'm sure the place worth another visit by a cloudy autumn day or better in winter.