It is the deepest lake in the Auvergne region.
The lake occupies a maar, a volcanic crater formed by an explosive interaction between groundwater and magma.
The deep water of the lake contains high concentrations of dissolved carbon dioxide, which is monitored by scientists as a potential degassing risk.
The lake's water chemistry is unique because it never undergoes a complete seasonal turnover.
Underwater springs feed the lake, maintaining its exceptionally high water clarity.
The lake was formed during the most recent volcanic eruption in mainland France.
Lac Pavin is a volcanic crater lake located at an altitude of 1,197 meters in the Massif du Sancy. Formed approximately 6,000 years ago, it is the youngest maar in mainland France. The lake is nearly circular, spanning 750 meters in diameter and reaching a maximum depth of 92 meters. Its water is meromictic, meaning the deep layers do not mix with the surface layers, resulting in a stable, oxygen-depleted bottom zone. The surrounding landscape features dense beech and spruce forests accessible via a peripheral hiking trail. The site is a popular destination for sport fishing, particularly for Arctic char and brown trout. Steep crater walls surround the water, limiting wind-driven surface turbulence. It is part of the Parc naturel régional des Volcans d'Auvergne.
The viewpoint along the northern crater rim looking across the entire circular span of the lake.
Wear sturdy hiking shoes as the path around the crater can be uneven and occasionally muddy.
Bring a light jacket, as the altitude and forested crater floor keep temperatures significantly lower than in the surrounding valleys.
Visit the orientation table located near the parking area for a view of the Sancy massif peaks.
Attempting to descend directly down the steep crater slopes instead of using the marked footpath.
The access road is often restricted or closed during heavy winter snowfalls.
Swimming and water sports are prohibited to protect the lake's delicate meromictic ecosystem.
