The Avan Lake, in the Province of Qazvin, is situated in the historic Alamout area, home to the world-famous Alamout fortress, which was once the headquarters of the Ismaili sect, led by Hassan Sabbah between the 11th and 13th centuries.
The lake has a surface of 70 square kilometers (27 square miles) at 1,800 meters (5,905 feet) above sea levels. The Avan Lake is crystal clear and is solely supplied by underground spring discharges.
Fishing, swimming and sailing are the activities available during summer. The lakes surface freezes in winter and is suitable for ice-skating.