Plans to extend the open-air swimming pool in a park into a multi-functional leisure complex, the Sportplaza Mercator, met with opposition from local residents, who feared a loss of green space. Venhoeven’s radical design for a 71,000 m2 building almost entirely concealed in a green hill won them over. Not only the roofs are planted, so, too, are the facades which resemble green embankments. Where the building fronts onto the street, the green hill gives way to a glass facade, revealing the steel frame within.