IJsselmeer, Lake IJssel, alternative spelling: Lake Yssel) is a shallow artificial lake of 1100 km² in the central Netherlands bordering the provinces of Flevoland, North Holland and Friesland, with an average depth of 5 to 6 m. The IJsselmeer is the largest lake in Western Europe. The IJsselmeer is a freshwater lake fed through the Ketelmeer by the river IJssel, which gives it its name. It is mainly fed by water from the Rhine since the IJssel is a branch of it.