Lines of Communication
The search for Roman roads can become an obsession with both amateur and professional archaeologists, but it is an activity fraught with difficulty and there has been much speculation and wishful thinking, rarely supported by hard fact. In mountainous areas it was impossible for the Roman engineers to build roads on their preferred straight lines and the obvious routes through the passes have been re-used so often that it is rare for undoubted Roman work to survive. Thus, although the general line of the routes taken is reasonably well known, there are few stretches of road which can be unequivocally identified as Roman. One of the major problems in Snowdonia, unsolved despite many years of examination both on the ground and from the air, is the route taken between Brithdir and Pennal. There are many photographs in the Cambridge collection which are a result of a fruitless search for traces of a route going to the west of Cader Idris, partly following Ffordd Ddu. There is a plausible alternative, taking an inland route over Bwlch Oerddrws, but much of the detail still remains to be discovered.
From the small fortlet at Brithdir the Roman road via Rhyd Sarn towards Caer Gai is well known and it is clearly marked on Ordnance Survey maps. It has been suggested that a branch road from just east of Brithdir turned south across open moorland towards Bwlch Oerddrws, but this was difficult to prove because the presumed road lay under more recent trackways. This recent photograph confirms that there was indeed a Roman road, but it takes a lower curving line passing just above Cae’r Tyddyn and meeting the modern road at the foot of the steep climb up to Bwlch Oerddrws. From there the road would have followed the Dyfi valley, with an inland link to the fort at Caersws, and perhaps continuing to Pennal. Precise details of this route, however, still await confirmation.
On the open moorland near Pen y Stryd is the only surviving stretch of Roman road in Snowdonia which has the classic structural features of two parallel ditches with a raised roadway, or agger. The more direct line on the photograph is caused by the natural gas pipeline, constructed in the 1980s. Just off the foot of the photograph are two Roman tile kilns, which used local clay. Beyond this the road can be traced with certainty for only a short distance and the rest of the route from here towards the fortlet at Brithdir has been the subject of much speculation.