Lake Lacha Lake Lacha Lake Lacha () is a freshwater lake, located in the south of Kargopolsky District of Arkhangelsk Oblast in Russia, south of the town of Kargopol. It is the largest lake in Arkhangelsk Oblast, with a surface area of and a basin area of . Lake Lacha is the source of the Onega River, one of the major waterways of the White Sea basin. The etymological origin of the name is unclear. The river basin of Lake Lacha includes the southern and western parts of Kargopolsky District of Arkhangelsk Oblast, as well as north-west of Vologda Oblast. In particular,
Onega Bay of the bay there are the town of Belomorsk and the outlet of the White Sea-Baltic Canal. From the east, the bay is limited by the Onega Peninsula. In the south-east, the town of Onega is located close to the shore of the bay. Administratively, the coast and the islands are shared between Kemsky and Belomorsky Districts of the Republic of Karelia, and Onezhsky, Primorsky, and Solovetsky Districts of Arkhangelsk Oblast. Most of the minor islands, including all of Sumsky Skerries, belong to Belomorsky District. The Onega Bay coast was populated by Russians (Novgorodians, of whom the pomors are the