Lake Onega is a lake in the north-west European part of Russia, located on the territory of Republic of Karelia, Leningrad Oblast and Vologda Oblast. It belongs to the basin of the Baltic Sea, Atlantic Ocean, and is the second largest lake in Europe after Lake Ladoga. The lake is fed by about 50 rivers and is drained by the Svir River.
There are about 1,650 islands on the lake. They include Kizhi, which hosts a historical complex of 89 orthodox wooden churches and other wooden constructions of the 15th–20th centuries. The complex includes a UNESCO World Heritage site, Kizhi Pogost. Eastern shores of the lake contain about 1,200 petroglyphs dated to the 4th–2nd millennia BC. The major cities on the lake are Petrozavodsk, Kondopoga and Medvezhyegorsk.
Coordinates 61°48'14.855" N 35°25'26.657" E