This monument is a large round cairn of prehistoric date high on the summit of the ridge known as Windy Gyle. It has wide views over the surrounding area, and can be seen as a major landmark from all directions. It was used to mark the boundary between England and Scotland. It is made of bare rocks and measures 14m in diameter and stands 2.2m high. The upper surface of the cairn has been re-arranged by walkers and there is a shallow hollow in the centre. Lord Russell is believed to have been murdered there in July 1585 by the Scots. This is a Scheduled Monument protected by law.