Partial cropmarks of the long suspected Roman fort under pasture at Gwernyfed Park have finally been revealed during the height of the drought on 19 July 2018. The fort is situated on level ground on the floor of the valley in close proximity to where the R.Dulas flows into the Wye. The area is occupied by the playing fields of Gwernyfed Park School and modern buildings. Roman iron smelting furnaces of first century AD date were excavated in this locality in 1951 by Lloyd and Savory in (Brycheiniog IV (1958), 53-71.)

Despite the severity of the drought, with the underlying geology of the site showing through the pasture, only fragments of the Roman fort's perimeter defences were revealed and nothing of any internal buildings. Given the presence of parchmarks at the southern end of the fort of modern drains and a semi-circular hardstanding ? presumably for athletics - it is likely the parkland here has been graded or landscaped.

The rounded bivallate SW corner of the fort is clearly marked, together with part of the bivallate defences on the NE side and a single ditch of the SE side of the fort, showing the fort measures 157m square (externally) and encloses approximately 2.5 hectares. The north-west corner of the fort has been lost under modern housing. The fort entirely encloses the site of the previously excavated iron works (NPRN 309372), now suggesting these form part of the fort's interior. The newly-identified Roman marching camp lies adjacent on the south-west side (NPRN 423861).

Another possible Roman fort has been located some 2km to the north at Glasbury (Davies & Driver Britannia 46 (2015), 272), whilst the large campaign fort, with a smaller fort within (Davies & Driver 2015, 271-72), lies some 8km to the NE at Clyro. The course of a putative Roman road lies some 375m to the north. Parchmarks some 300m to the south-east of the Three Cocks fort, also discovered on 19 July 2018, show the line of the Roman road (NPRN 423860) approaching the fort; a projected alignment shows the road would pass the south side of the fort to within 115m of the south gate suggesting a T-junction would once have existed here.

It has already been suggested (Davies & Driver 2015, 271-72) that an early Roman communication route linked the complex at Clyro and the newly discovered fort at Cefn-Brynich. The discovery of another fort at Three Cocks, together with a stretch of possible Roman road, adds further credibility to this suggestion. Whether the Three Cocks fort belongs to the same pre-Flavian era as Cefn Brynich is unclear. On the basis of the associated ceramics Lloyd and Savory suggested a Flavian date for the furnaces (this requires checking!). Given the apparent bunching of sites between Three Cocks and Clyro it is unlikely that these were exact contemporaries and must, therefore, represent differing episodes in pre-Flavian and early Flavian operations in this part of Wales.

T. Driver and J. L. Davies, March 2019.