Earthwork platform to north-east of ruined buoy-keeper's cottage (NPRN 421571), sited only 1 metre above the high water mark of a small inlet or bay on the south side of the Skerries. The platform is a slightly curving 'C' shape, measuring 19.3m south-west to north-east, and 7.2m wide at its central point. On the south-west side it adjoins the ruined cottage, and its side measures 5.2m. The ruined cottage walls spring from the footings of the platform and it appears that material may well have been robbed from the (?earlier) platform to build the cottage. On the north-east side the side of the platform measures 8.9m externally. The platform is built into the slope on the north-west side, partly defined by a natural outcrop. Here there are remains of a tumbled stone wall defining its northern, rear, corner. Along its front, south-east, side it is defined by a 0.5m high earthwork scarp, partly revetted in places, and overlooking the small coastal inlet.

The interior of the platform is heavily burrowed by rabbits, although a small 'hearth' setting of earthfast stones c.1m across may be an original feature. A low 0.25m high mooring post, formed of an upright stone, lies just to the north-east.

The curving shape of the platform - rather than a rectangle - is problematic if one considers it to be the remains of a building. However, the structural remains of tumbled walling and a revetted front to the platform suggests this may be the site of a building rather than perhaps a terrace associated with the mooring or storage of boats. It appears to be an early structure in character, when compared to the upstanding ruins of the buoy-keeper's cottage. It may perhaps pre-date the main phase of occupation of the island (for its lighthouse) from the 17th century onwards.

Visited by T. Driver, RCAHMW, 19 April 2016.