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 Otradnoye Lake Otradnoye Lake Otradnoye (; ) is a lake on Karelian Isthmus, in Priozersky District of Leningrad Oblast, south of the town of Priozersk. The area of the lake is , and the area of its drainage basin is . The lake is the source of the Pionerka River (Pyhäjöki River) which flows to the west and drains into Lake Komsomolskoye. In its turn, Lake Komsomolskoye drains into Vesyolaya River, a tributary of the Vuoksi River. Whereas the lake belongs to the basin of Lake Ladoga which is located about to the east, its outflow runs to the west. The