The Veluwe is a forest-rich ridge of hills (1100 km²) in the province of Gelderland in the Netherlands. The Veluwe features many different landscapes including woodland, heath, some small lakes and Europe's largest sand drifts. The Veluwe is the largest push moraine complex in the Netherlands, stretching 60 km from north to south, and reaching heights of up to 110 metres. The Veluwe was formed by the Saalian glacial during the Pleistocene epoch, some 200,000 years ago. Glaciers some 200 metres thick[citation needed] pushed the sand deposits in the Rhine and Maas Delta sideways, creating the hills which now form most of the Veluwe. Because the hills are made of sand, rain water disappears rapidly, and then it flows at a depth of tens of metres to the edges where it reaches the surface again.