Large lake basin situated in the valley between the Bondone Mount group and the Baldo Mount one, which contained the Loppio Lake until 30 years ago. In the background of the ancient lake a vegetation very rich in wet grasslands and swamps has now developed, where also white willows grow.
Along some stretches of the shores there are peats having a rare Cyperaceae vegetation. There are habitats of particular interest which are not included in the Annex I of the Habitat Directive: Caricetum elatae (Magnocaricion) (5%), Alnetea glutinosae (10%), Phragmition (15%). Noteworthy is the presence of the priority habitat 6210 (wonderful orchid flowering) covering the 2% of the Site.