Kostomuksha (Russian:Костому́кша; Karelian:Koštamuš; Finnish:Kostamus) is a town in the northwest of the Republic of Karelia, Russia, located 30 kilometers (19mi) from the border with Finland, on the shore of Lake Kontoki. Population: 28,436(2010 Census);29,746(2002 Census);30,432(**** Census).