The Markermeer is a  lake in the central Netherlands in between North Holland, Flevoland and its larger sibling, the IJsselmeer. A shallow lake at some 3 to 5 m in depth, it is named after the small former island, now peninsula, of Marken that lies within it. The southwest side of the lake that begins where the IJ once emptied into the Zuiderzee is known as the IJmeer.