Beemster (Dutch pronunciation: [ˈbeːmstər]) is a former municipality in the Netherlands, in the province of North Holland. The Beemster is the first so-called polder in the Netherlands that was reclaimed from a lake, the water being extracted from the lake by windmills. The Beemster polder was drained between 1609 and 1612. It has preserved intact its well-ordered landscape of fields, roads, canals, dykes and settlements, laid out in accordance with classical and Renaissance planning principles. A grid of canals parallels the grid of roads in the Beemster. The grids are offset: the larger feeder canals are offset by approximately one kilometer from the larger roads. Beemster merged into the existing municipality of Purmerend on 1 January 2022.