The lake is anthropogenic, created at the time of the excavations for the railway of the Frejus in 1871, then exploited as icebox and as a tourist site in the first years of the twentieth century, due to the thermal waters. Its naturalistic importance is due to the presence of numerous botanical species linked to humid (orchids as Epipactis palustris and Dactylorhiza incarnata bloody and one of the rare stations of Iris sibirica in Piedmont), but above all to its fauna: from common toad, the grass snake up the rare freshwater crayfish (Astropotamobius pallipes).
Are well 18 species of dragonflies surveyed, including Sympetrum vulgatum, for which this site is the only known station in Piedmont, and a rare beetle for Italy, the Philochthus mannerheimii. Also birds exploit these waters as place stage during migrations, for which were observed species typical of the reeds, as the cannaiola green and the cannareccione.