Arkhangelsk Oblast the south-west of the Oblast drains into the Kema River which belongs to the basin of the Caspian Sea. The area in the Onega River basin containing the biggest lakes in the oblast, such as Lake Lacha, Lake Kenozero, Lake Undozero, and Lake Kozhozero. The tundra of the Nenets Autonomous Okrug also contains a number of bigger lakes. The river basin of the Pinega is characteristic of the karst, with a number of caves in the region. The White Sea coast within the Oblast is split into the Onega Bay (where the Onega is the major tributary), the Dvina Bay
Arkhangelsk Oblast and the selo of Leshukonskoye, and there are still no roads into the Nenets Autonomous Okrug, on the left bank of the Onega downstream from Severoonezhsk, and very few roads on the right bank of the Northern Dvina. Many rivers can only be crossed by ferry boats, which means they cannot be crossed during the ice melting period. There is regular bus service on the main roads. The principal railway line in the oblast is the railroad connecting Moscow and Arkhangelsk. The piece between Vologda and Arkhangelsk was constructed in 1890s and passed through previously uninhabited areas between the valleys