Every so often as you cycle around the woods here, you come across a large mound.grafheuvel Often the trees and shrubs have been cleared from it. These are burial mounds from prehistoric times. At the name implies, they were burial chambers, often for several people together. Their age varies from bronze to iron to stone age. Near Wageningen they are mostly bronze age (3000 - 800 BC). These ancient monuments have legal protection. It permitted to walk on them, but is best not to take your mountainbike over them as that will erode away the outer surface.