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 also navigable in the lower course. The Onega is not navigable except for the two relatively short stretches because of the rapids. However, except for the lower course of the Vychegda and some parts of the Northern Dvina, there is currently very little or no regular passenger navigation on these rivers. They are used for cargo traffic though. In 1765, a road was built between Saint-Petersburg and Arkhangelsk, mainly for postal service. The road still exists and passes Kargopol and Plesetsk, and it has been paved in 2011. One of the principal highways in Russia, M8, connects Moscow and Arkhangelsk,