Lake Ladoga Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitution to Russia by the Treaty of Nystad. Later, in 1812–1940 the lake was shared between Finland and Russia. According to the conditions of the 1920 Tartu Peace Treaty militarization of the lake was severely restricted. However, both Soviet Russia and Finland had flotillas in Ladoga (see also Finnish Ladoga Naval Detachment). After the Winter War (1939–40) according to the Moscow Peace Treaty, Ladoga, previously shared with Finland, became an internal basin of the Soviet Union. During the Continuation
Lake Sevan cultural monument is the Sevanavank monastery located on the peninsula, which was until the mid-20th century an island. Another prominent monastery at the western shore is Hayravank, and further south, in the village of Noratus, is a field of "khachkars", a cemetery with about 900 "khachkars" of different styles. Additional "khachkars" are found at Nerkin Getashen on the south coast. Sevan trout ("Salmo ischchan") is an endemic species of the lake, but it is endangered as some competitors were introduced into the lake, including common whitefish ("Coregonus lavaretus") from Lake Ladoga, goldfish ("Carrasius auratus"), and crayfish ("Astacus leptodactylus"). If the