Lac de Plan d’Aval is a high mountain reservoir at an elevation of 2.041m (6,696ft) above the sea level, located in the Savoie department in the Rhône-Alpes region in south-eastern France.
Located on the southern slope of the Massif de la Vanoise, within the Parc National de la Vanoise, the road to the reservoir is totally paved. It’s called D108-Route des Barrages. The road was built between 1945 and 1956. Starting from Aussois, the ascent is 6.8km long. Over this distance the elevation gain is 558 meters. The average gradient is 8.20%, with sections up to 11.8%. The road ends at a big parking lot.