Ackerdijkse Plassen is a nature reserve in Oude Leede, a village in the municipality of Pijnacker-Nootdorp, (south of Delft and west of Berkel en Rodenrijs). It is one of the most important bird areas in the Netherlands. In addition to 115 species of breeding birds, the ponds are visited annually by about eighty species of migratory birds, such as greenish warbler, Greater short-toed lark, short-eared owl, booted eagle, lesser spotted eagle, black crowned night heron and osprey.