Hidden above Lac Vert, Lac Bleu with its dam feeds the Portillon power station (at the bottom of the Vallée du Lis) built in 1941. It is one of 6 power stations in the Luchonnais.
Leave the Vallée du Lis car park, cross the footbridge and climb through the heathland to the Pré de l’Artigue. Under the Coume hut, turn right towards Lac Bleu. Further up, at the fork in the road, turn left to reach the lake (herds of cattle with patou).
