The ridge runs from northwest to southeast and is about long and an average of wide. The highest point is the Kettelberg which is sea level (NN) high. The Gehn forms a link between the Wiehen Hills and the Ankum Heights (Ankumer Höhe). It is largely forested and is not - like the Ankum Heights- part of a series of ice age terminal moraines from the latest event of the Saalian glaciation, the so-called Drenthe I stage, but is a ridge of Jurassic rock that was pushed up during the folding towards the end of the Cretaceous period.