The tunnel valley can be recognized today by the large elongate shapes of lakes Flyndersø and Stubbergård Sø. It is evident that the lakes consist of several sub-basins separated by spits or tongues. Each basin represents a large kettle hole and the spits and tongues indicate the intervening areas. The presence of two interposed types of landscape is evident in Figure 16-2. The section through Hjelm Hede shows the underlying glacial landscape with a tunnel valley overlain by an outwash plain below lake Flyndersø. Scattered in the landscape are many smaller kettle holes (Figure 16-3). East of the tunnel valley system the morphology is similar to an undulating moraine landscape (Figure 16-1). Geologists have not yet verified this, but it is likely that these moraines were partly preserved in the dead ice landscape and were consequently not completely removed by the flowing masses of meltwater.
Pollen analyses from the bogs reveal how the vegetation has evolved since the end of the ice age. In the Stone Age, about 7000 years ago, deciduous forests, dominantly oaks, covered the area. Since then people have cleared the forests and impoverished the soil. In the 1700’s this resulted in the area being completely dominated by heather-covered heathland. Extensive planting of the heathlands has been carried out, but a large part of Hjelm Hede remains as heather-covered heathland and is maintained as representative of this type of cultural landscape. In other places the natural oak scrubland is allowed to develop.