Lake Iznik (in Turkish: İznik Gölü), which is the fifth largest natural lake in Turkey and one of the places of tourism in Bursa, where it extends over a distance of 32 km in length and 10 km in width and has a depth of 80 m.

 The city of Iznik, known by its historical name Nicaea, is located at the eastern end of the lake, and the ancient Greek name for this lake was Askania.

Lake Aznik is a source of fresh water and streams, as it contains many rare plants and was known in the past as rice cultivation.