Existence because of the Afsluitdijk
The area above Koudum, along the IJsselmeer coast into the direction of Makkum has its very own character. Outside the dike there is string of waarden, areas of shallow coastal waters. The waarden appeared after the construction of the enclosing dike, the Afsluitdijk. Due to this the tide disappeared in the area; the salt water slowly turned into sweet water and the water level dropped down. This resulted in dry sandbanks, the waarden, before the coast. A part of these sandbanks turned into a natural area and other parts were set up as cultural landscape.
Nowadays it is a varied area with grass landscapes, reed plots, swamps, shelf beacons and cultivation. In 1991 the area became a natural monument, because the area harbours so many natural waarden. The natural monument is especially important for lots of bird species. Thousands of birds moult, rest, breed and eat within this wide natural area. The area has such a huge force of attraction to birds, because there is enough food to find, very little disturbance and there are many sandbanks.