The first plan for a park round a lake left by peat excavation in the Kralingen district dates from 1911 and was conceived by the director of Public Works G.J. de Jongh. The shores of the lake were raised with sludge accumulated from digging two large harbour basins (Merwedehaven and Waalhaven). This park was seen as compensation for the lack of green space elsewhere in the city. A new plan voluntarily drawn up by Granpré Molière, Verhagen and Klijnen for a wooded park was partly put into practice, whereupon Koops and Bijhouwer, two new designers at the Public Works office, addressed themselves to the design, adding among other things a beach for bathing and a new ring road. Several sports facilities (for athletics, equestrian sports and golf) were delegated to the outer edges of the park. Further to these, two windmills were reconstructed and two villas built. The plan was executed during the crisis years of the 1930s by unemployed workers, though the park would only be officially opened in 1953.