NGRef: SH4745
OSMap: LR115/123
Type: Camp
None identified
SH477454 350+ x 138+ ft
(107+ x 42+ m)
c.1½-15 acres
(c.0.66-6 ha)
This camp is known only from a 138 ft. (42 m) length of the north-west side, the rounded western corner-angle, which has a radius of 43 ft. (13 m), and around 350 ft. (107 m) of the south-west side. The area enclosed by the visible defences is just over 1½ acres (0.6 ha), but the size of the corner-angle indicates a larger encampment and there is space sufficient here for one of around 15 acres (6ha). The rampart survives in places 10 ft. wide, though barely 1 ft. high, fronted by a ditch 8 ft. across.

This camp lies on the western bank of the Afon Dwyfach less than ½ mile to the north-east of the Pen Llystyn fort. It is very likely that the camp was the first Roman military establishment in the area, probably during the first campaign season of governor Gnaeus Julius Agricola sometime in the late-Summer of 77AD or 78. The camp preceeded the nearby fort by a year or less.

See: Air Reconnaissance in Britain, 1969-72 by J.K. St. Joseph in J.R.S. lxiii (1973) p.241;

Click here for a map of Derwydd Bach from

Page Citation: Kevan White (2018) "Roman Britain: DERWYDD BACH CAMP"