The earthworks at Allt y Fern are thought to represent a medieval motte and bailey castle superimposed upon an earlier promontory enclosure: the motte is a near-circular steep-sided mound, 27-8m in diameter & rising 6.0m to an 9.0-10m diameter summit, ditched about on all sides; it is inset into the eastern angle of a subrectangular enclosure some 52m north-east to south-west, having a north-east facing rampart & ditch beyond which a further roughly 84m sweep of rampart and ditch covers both motte and bailey from the level ground on this side; the remainder of the enclosure is defined by scarps above steep natural slopes, a 25m section of ditch cutting off the 50m tail of the promontory: OS County series (Carmarthen. XXXII.15 1889) appears to show a 9.0m diameter circular structure set upon the summit of the mound, which is surrounded by a 25m diameter boundary, apparently set at the base of the ditch: these last features may be associated with Plas Alltyferin (Nprn120788).

J.Wiles 24.03.05