Lake Sapanca (Turkish: Sapanca Gölü) is a fresh water lake in Turkey, between the Gulf of İzmit and the Adapazarı Meadow. The lake has a catchment area of 251 km2, surface area of 45 km2, a length 16 km east–west / 5 km north–south, and a maximum depth of 52 m.
Sapanca Lake is located on a tectonic hole, which is situated between Izmit Bay and Adapazari Meadow and runs parallel to Iznik Lake.
Lake Sapanca is surrounded by mountains in the south and small hills in the north. Water is taken from the lake for domestic and industrial needs.
The region around Sapanca is an important destination for day trips and weekend vacations.
