
At the foot of Molard de Netru, where the Bienne meets the Ain, is the Coiselet Lake. This lake is a 10-kilometre-long artificial lake created in 1970 when a hydropower dam was built. This lake is marked on its western edge by the Pic d’Oliferne, with an altitude of 807 m and on which a castle was built in the 13th century, now mostly in ruins.