Boyuk Alagol (Azerbaijani: Böyük Alagöl) is a lake of Azerbaijan. It is located on the Karabakh volcanic plateau, in Kalbajar Rayon. Since 1993, it has been under occupation by Armenian forces. Its area is 5.1 square kilometres (2.0 sq mi) and the volume of water reaches 24.3 cubic metres (860 cu ft).