 It consisted of one burial chamber constructed of large upright slabs, capped by two lintel slabs, forming a chamber of 15 feet (4.5 metres) long, 3 feet (0.9 metres) wide and 3 feet (0.9 metres) high, covered by a huge mound of stones and turves.The cairn was aligned almost exactly North-South, with the burial chamber under the wider northern end.At the northern edge of the cairn, a double wall could be made out, curving inwards to form an entrance to a forecourt.