Located a few kilometres from Besse en Chandesse, Lake Pavin is a very deep volcanic lake (301 feet, 92 metres). Its waters have the rare quality of not mixing, unlike most other lakes which are regularly fully stirred, homogenised, and therefore oxygenated. The deepest waters of Lake Pavin, below 213 feet (65 metres), are stagnant and form a sort of second lake with a very particular chemical composition.