In the tenth century Zoetermeer was a small village primarily home to farmers and fishermen. In the 13th century a village center was formed, which still exists as the historic Dorpsstraat. Until the 17th century there was a lake called the Zoetermeer. A reminder of this is the "Zoetermeerse Plas" in the Noord Aa recreation area at the northern edge of town; this artificial lake was created when tons of sand were needed to lay the foundation for new housing development, and the area north of Zoetermeer was a good source of this resource.