Lac d'Allos is a high mountain lake at an elevation of 2.248m (7,375ft) above the sea level, located in the Alpes-de-Haute-Provence department in the Provence-Alpes-Côte d'Azur region of southeastern France.
Located in the center of the French Maritime Alps, in the heart of the Mercantour National Park, it’s the biggest high-mountain-lake in Europe. The lake water is essentially from melting snow and autumn rains. Near the lake there’s a mountain lodge called Refuge du lac d'Allos.
The road to the lake is closed from October to June (weather permitting). It’s pretty steep, with some sections up to 16.0%. Starting from Allos, on the D908 road, the ascent is 11.3 km long. The first 9.5km are asphalted. At the end of the road you will arrive at a parking lot, called “parking du Laus”. Beyond this point, motor vehicles are banned. The last 1.8km are gravel, but driveable by 4x4. The elevation gain is 830 meters. The average gradient is 7.34%.