A rectilinear, dry stone structure, measuring 4m north northwest - south southeast by 3m. The walls stood up to 0.15m high, although no wall was visible on the south southeast side. The vegetation cover was grass and reeds when the feature was recorded in September 2007. The dating of the feature is uncertain. It lies within an area occupied by many features connected with the construction of the reservoir in the early 20th century but the dry stone build suggests an earlier structure. J.J.Hall, Trysor, 27 September 2007