During the last Ice Age, polar winds blew sand from the north to Brabant, where it remained in thick packets. For a long time this sandy plain was covered with primeval forests. Until in the fourteenth century the trees were cut down by people. These used the wood as fuel. The barren plain filled with heathland, on which farmers grazed their cattle. This intensive grazing and sodding depleted the soil. This gave sand free rein. For a long time, the sand was a major problem for the inhabitants. Villages and fields threatened to disappear under it. Trees were planted to stop the encroaching sand. You can still see traces of this today: find the undergrowth of the trees, whose crowns alone still protrude above the sand hills.