Rectangular terraced structure surviving on southern side of rock outcrop, on south-east Skomer. The earthworks lie in heavily burrowed ground of former puffin burrows, so are difficult to trace on the ground. They are visible on 2001 Royal Commission aerial photographs and were inspected during a field visit to Grassholm on 14th October 2012. On the upper, northern part is a raised rectangular platform measuring approx. 8m x 6m, set within a larger rectangular walled/embanked enclosure measuring 20m x 13m, with a smaller rectangular extension on the south-east side. The enclosure is defined by a row of orthostats on the south-east side. The complexity of the structures suggest perhaps several phases of construction and alteration. A date for the structures is uncertain.

T. Driver, RCAHMW, 17/10/2016