The limes stood along this edge of the forest from around 100 until the third century AD. The model shows a typical (albeit not true to original!) wooden tower as they were built during the first phase of the limes. Later these towers were replaced by stone towers. This is visualized by the reconstructed foundations of one such tower, 50m to the north west. Unfortunately the tower is not open to public any more.
[Source: Sign near the wooden tower, wikipedia.de]