Source du Groin, ENS de l'Ain

The Groin spring is one of the geological curiosities of the Valromey, awarded the "ENS" label by the Ain department in 2016. Real natural and landscaped jewels of the Ain department, sites with the ENS "Espaces naturels sensibles" label are managed in such a way as to preserve the biodiversity they host, and developed for opening to the public (barring exceptions due to the fragility of the environments).

The water that flows out of the basin comes from underground streams formed by the infiltration of rainwater from the Haut-Valromey and Plateau de Retord. Depending on the period (dry or rainy), the basin is more or less full of water, or even empty. The differences in level are impressive. In the rainy season, the siphon opens with a frightening roar, and the water flow at the siphon outlet can reach 5m3 per second.

To protect this sensitive natural area, it is forbidden to swim in the groin or picnic on the site or along the banks.

Pets allowed on leash only.