Göygöl (Azerbaijani: Göygöl, literally "the Blue Lake") is a natural impounded lake in Azerbaijan. Due to an earthquake which hit the area on 25 September 1139, parts of the Kapaz Mount collapsed and blocked the path of the Kürəkçay River. As a result of diversion of water flow, a lake with pure mountain water was created, hence the name given signifying the pureness of the water.