A concrete pad measuring 4.1m west northwest - east southeast by 2m and raised 0.25m above the ground. At its west northwest end it had two steel girders angled into the pad and pointing towards NPRN 267148. On the eastern portion of the pad was a raised square of concrete, c. 1.3m in diameter and 0.10m high with a metal threaded rod protruding form the main concrete just beyond the corners of the raised area. It was thought to be connected with NPRN 267148 and with the construction of the Grwyne Fawr reservoir in the early 20th century. When recorded in September 2007, the vegetation around the feature was largely reeds. J.J.Hall, Trysor, 27 September 2007