Onega River traditionally explained as related to Finnish "Enojoki" - the main river, stream. In terms of both area of the basin and the average discharge, the Onega is the third river basin of the White Sea (behind the Northern Dvina and the Mezen. The river basin of the Onega is spread over the west of Arkhangelsk Oblast, north-west of Vologda Oblast, and also includes minor areas in the east of Republic of Karelia. The Onega basin includes some of the biggest lakes of Arkhangelsk and Vologda Oblasts, such as Lake Vozhe, Lake Lacha, Lake Lyokshmozero, Lake Kenozero, Lake Undozero, and Lake
Onezhsky District Porog; there is regular passenger navigation. There is also limited passenger service on the Onega Bay. Onega is served by the Onega Airport which has weekly passenger flights to Arkhangelsk and to the "selo" of Purnema on the Onega Peninsula. Onezhsky District has a very high concentration of historical, archaeological, and architectural monuments. The district contains thirty-two objects classified as cultural and historical heritage by Russian Federal law, and additionally eighteen objects classified as cultural and historical heritage of local importance. Most of these are wooden churches and chapels. The monuments classified as historical and architectural heritage are the following: