Leningrad Oblast of two great lakes of the European Part of Russia, Lake Ladoga and Lake Onega. Its northeastern part, between the Gulf of Finland and Lake Ladoga, occupies the Karelian Isthmus. Some islands in the Gulf of Finland (including Kotlin, on which the city of Kronstadt has been built) and Lake Ladoga (including Konevets) also belong to the oblast. Much of the area of the oblast belongs to the drainage basin of the Neva, which is the only outflow of Lake Ladoga. Whereas the Neva, which flows to the Gulf of Finland (the city of Saint Petersburg is located in its
Lake Ladoga 837 km (earlier estimated as 908 km). There are around 660 islands, with a total area of about 435 km. Ladoga is, on average, 5 m above sea level. Most of the islands, including the famous Valaam archipelago, Kilpola and Konevets, are situated in the northwest of the lake. Separated from the Baltic Sea by the Karelian Isthmus, it drains into the Gulf of Finland via the Neva River. Lake Ladoga is navigable, being a part of the Volga-Baltic Waterway connecting the Baltic Sea with the Volga River. The Ladoga Canal bypasses the lake in the southern part, connecting the