Dvina Bay streams. There are many small islands in the Dvina Bay as well, the biggest being Mudyug Island. A national park, Onezhskoye Pomorye National Park, was open on the Onega Peninsula on 26 February 2013. The Dvina Bay is limited by the Onega Peninsula from the west. At the eastern side, the shore steeply rises to a plateau (White Sea - Kuloy Plateau) which drains east into the Soyana, a major tributary of the Kuloy. The Onega Bay shore is often referred to as "Letny Bereg" (Summer Coast), and the eastern shore of the bay is "Zimny Bereg" (Winter Coast). The
Arkhangelsk Oblast most of these became unprofitable and have been destroyed. In the 1970s and 1980s the aviation was active, with all district centers connected to Arkhangelsk with regular flights, Kotlas being the second important hub. Currently, it has almost disappeared. There are two airports in Arkhangelsk, but regular local flights are only carried out to the destinations which do not have rail or road connections, such as Novaya Zemlya, Solovetsky Islands, the Nenets Autonomous Okrug, the Onega Peninsula, and the north of the oblast. The exceptions with functioning airports are Mezen, Leshukonskoye, and Onega. The oil transport system, Baltic Pipeline System,