From the Introduction
The small stream flowing along in its bed has been the natural border between two realms for a long time. Recently relations between the two realms have turned sour and the ruler of one realm saw the need to establish a more formal border and to fortify it at the same time. For this reason he has started to construct small fortifications all along the former natural border.
Here a small moat, filled by the small river, has been dug and the excavated earth has been used to raise a small motte inside the moat. Its top is crowned by a simple stone watchtower and a low wooden palisade. A set of slippery earthen stairs leads down to the simple wooden bridge across the moat. A number of sharpened stakes at the bottom of the motte and hidden under the water of the moat are the only other defence of the small fort.