Saimaa is a lake in southeastern Finland. At approximately 4,400 square kilometres (1,700 sq mi), it is the largest lake in Finland, and the fourth largest natural freshwater lake in Europe. It was formed by glacial melting at the end of the Ice Age. Major towns on the lakeshore include Lappeenranta, Imatra, Savonlinna, Mikkeli, Varkaus, and Joensuu. The Vuoksi River flows from Saimaa to Lake Ladoga. Most of the lake is spotted with islands, and narrow canals divide the lake in many parts, each having their own names (major basins include Suur-Saimaa, Orivesi, Puruvesi, Haukivesi, Yövesi, Pihlajavesi, and Pyhäselkä). Thus, Saimaa exhibits all major types of lake in Finland at different levels of eutropification.