On the summit of an isolated hill surrounded by the 90m contour and overlooking the village of Llanberis, are the remains of an oval camp protected by a single stone vallum, measuring about 90m from west-south-west to east-north-east, and 30m across at its maximum width. The position is one of remarkable strength, for along the whole of the northern side the cliffs are 60m high and very precipitous. Yet it is on this side that the only stretch of well-preserved walling is to be found. The external rampart masonry consists of large facing stones each measuring up to 1m wide by 1m high, with smaller packing stones set behind them. The site is very poorly preserved at ground level.

Source: Caernarvonshire Inventory Volume II, 169 (1136).
RCAHMW, June 2009

Sections of the drystone field wall on the south and east side of the knoll incorporates some substantial orthostats along its base, suggesting that the existing 19th century walling may be a rebuild of much earlier fabric.

Information from Paul R Davis, December 2021.