The Markermeer (Dutch pronunciation: [ˌmɑrkərˈmeːr]) is a 700 km (270 sq mi) lake in the central Netherlands in between North Holland, Flevoland, and its smaller and larger neighbors, the IJmeer and IJsselmeer. A shallow lake at 3 to 5 m in depth, matching the reclaimed land to its west, north-west and east it is named after the small former island, now peninsula, of Marken on its west shore.
The Markermeer was not originally intended to remain a lake. It was formerly part of the Zuiderzee, a saltwater inlet of the North Sea, that was dammed off by the Afsluitdijk (Closure Dike) in 1932, turning the Zuiderzee into the freshwater IJsselmeer. The following years saw the reclamation of extensive tracts of land as large polders in an enormous project known as the Zuiderzee Works. One of these, the Markerwaard, was to occupy the area of the current Markermeer. Part of the construction of this polder was building the Houtribdijk, also called Markerwaarddijk, finished in 1976, which hydrologically splits the IJsselmeer in two, the southern section being the Markermeer.