This fort measures 600 feet from north-east to south-west by 515 feet transversely (c.183 x 157 m), covering an area of 7 acres (c.2.8 ha). It has a triple-ditch defensive system backed by a rampart of turf packed with gravel and clay. The defences at the western corner-angle were sectioned in 1976; the outermost ditch was not dug, the median ditch was V-shaped, and measured 8½ ft. wide by 4½ ft. deep (c.2.6 x 1.4 m), separated from the outer ditch by a gap of about 10 ft (3 m) and from the inner by a gap of 11 ft. (c.3.3 m), the inner ditch was also V-shaped, 9½ ft. wide and 5½ ft. deep (c.2.9 x 1.7 m). The rampart, between 13½ and 16½ ft. broad (c.4.1-5.0 m), was perhaps revetted at the rear with timber. A field-oven and a pit of food-waste was covered by the rampart-spread, which had been deliberately slighted into the inner ditch. Scarce pottery finds seem to indicate a brief occupation during the Flavian-Hadrianic period.
References for Pen Llwyn
- Air Reconnaissance in Britain, 1973-76 by J.K. St. Joseph in J.R.S. lxvii (1977) pp.152-4 & figs. 16/17;
- Britannia ix (1978) p.408;
Map References for Pen Llwyn
NGRef: SN6580 OSMap: LR135