Margary RR67 (part) Canovium (Caerhun) to Segontium (Caernarfon)

For a road that is listed in the Antonine Itinerary parts of this route remain elusive, despite the abundance of milestones associated with it. Most of it coming up from Canovium/Caerhun to Bwlch Ddeufaen is well established, and a milestone was found in 1954 in the vicinity of SH71987155, GAT4688. This relatively high level pass (1375ft=419m) is historically the safest way of reaching north West Wales, since it avoids the difficulties of travelling down the coast from Conwy (itself founded by Edward I with the building of the castle) past Penmaenmawr and Penmaenbach, where there is a history of unwary travellers falling in to the sea. The prehistoric standing stones GAT523 suggest the Romans were not the first to use it as a long distance route. See my separate article Ashton’s Road to Parys Mountain. The same course is used by the National Grid powerlines established in the 1930s, and the wide well established track that is generally referred to as the Roman road on OS maps was utilized with some modifications to enable their construction. The route was also included in a turnpike Act of 1777, and possibly some work undertaken.

Travelling west from the top of the pass there are indications where the older route is visible to one side or the other of modern track. By a ford SH70307207 there is an upstream zigzag, and W of this the earlier course is marked by a hollow on N side of present track. After a second ford at SH69927222 the modern route bears to the south uphill, crossing the shoulder of Yr Orsedd SH69307224. However 1891 marks a separate track to N, following the contour in an arc above the more direct stone wall up to the crest at SH69207251. All that is visible on the ground is a sheep track, but this might reflect the presence of drier ground at the outer edge of a filled in terrace. It is no longer marked as a path.

The section in italics I walked and described before the road was proved along this route by excavation at SH69437236 (GAT 217571), SH69437228 (GAT 17572), SH67807257 (GAT17841). The crest seems significant because it an excellent aiming point from Gorddinog below, a clear saddle in the profile of the spur of the mountain. The three milestones found on or near the Gorddinog route, two at GAT4066 SH67907295 (there is a replica in the field of one of them), 2nd and 3rd centuries, and at Madryn SH66887338 GAT368 (“possible milestone”), plus its very clear military advantage going down a spur of the mountain with extensive views, seems conclusive enough.

At this point Margary’s text seems confused, because he refers to a narrow terrace zigzagging down to Gorddinog. His source, it is unlikely he would have walked it himself, is Hemp, and that text, which describes what was known of the road at the time, but in the reverse order, clearly states the route via Gorddinog because of the milestones GAT4066, which were discovered in 1883, but it doesn’t mention the zig zags. I suspect what Margery saw were the zigzags above the end of the tarmac lane SH67607160, where there is now a small parking area. Even now some OS maps mark them as the course of the Roman road. Such a series of zigzags is a familiar feature of packhorse trails, eg above Beddgelert SH58644709 and elsewhere, and these are narrow and slightly hollowed, with no evidence of a constructed road. This line is littered with cairns, enclosures etc of uncertain date, so the route may even have existed before the Roman period. The tarmac lane which goes down via Bont Newydd and on to Aber is referred to in 1652 GAS XQS1652/156, where it is called “hwylfa gogvfryn” (? halfway valley)

Returning to the direct route, there is a track continuing the line down from the spur although it curves away N at SH68857272. The straight on course is very steep although it does show from below as a grass sward in the heather, so there might be metalling underneath. Either that, or a small zigzag as shown on 1891. A wall comes onto line at SH68797269, and the route is marked as a footpath on 1891 and right of way on current maps , and as a road throughout on 1838, although noone seems to walk on it now, due no doubt to its inaccessibility further down. From SH68357285 on it develops as a very wide deep hollow way into which rocks to clear the surface for pasture have been dumped, petering out at SH67967309. The right of way to S at this point, which does have a stile, goes through a wood to Rhiwiau Isaf, but this is now a riding school and the wood is used as stabling for a large number of horses, which makes it very wet, slippery, and potentially dangerous. The wall goes straight on to a T junction at SH67867330, although the ground is now featureless. Beyond the junction there is a right of way running at right angles, but there is no path and it is blocked at SH67757327 by a barbed wire fence. Below the fence however a wide slightly hollowed terraceway continues down the hill turning slightly N of W, and is accessible from the by road below by a stile at SH67607322. This runs out into the field where there are no visible traces.

Once the low lying land is reached, there are no obvious traces at first. The terraceway at Pen y Bryn SH65707283 GAT11168, is considered to be an early version of the turnpike.

The next evidence is somewhat to SE of this alignment, approaching the farm Henffordd SH65227232. There is a footpath leaving the byroad to Bont Newydd (which itself is the continuation of the later diversion described above) at SH65787248 (not the track going straight up the shoulder of the hill) and curving round the hillside to the farm. At SH65527255 it is joined by another path coming up from the village past Tan yr Allt, which would be a better link to the terraceway on the other side of the river, although there is no field evidence as such on it. From this point on there is a succession of evidence running SW, and seen from vantage points on the A55 below the guiding principle seems to be that the line runs in the angle between the mountainside and the coastal plain, which is often the break point between cultivation and rough pasture. There are a number of farms on this line, whose only access now is by individual tracks from the N, which could be of significance.

Slightly further down the plain is the byroad from Aber church, which runs to Crymlyn (marked here by 1891 rather implausibly as Roman Road, considering it is formed of a series of right angled bends), then below the former Penrhyn Estate stables at Tyn yr Hendre, St. Cross church, down a hollow way at SH60657085 which was truncated by the railway in 1849 (by which time the turnpike would of course have superseded it) and across the Ogwen at Tal y Bont. There is then a by road/footpath recrossing the railway to the upper part of Llandygai, and a footpath between the railway and Industrial Estate to a crossing of the Cegin at SH58827115, with a hollow way continuing up the hill, then a minor road on Maesgeirchen estate and a metalled track over Bangor mountain (which W, I think mistakenly, considers to be Roman) and down to the city. Presumably this is the pre turnpike route again. The by road and ford at the Cegin at SH58677065 could be a variation of this – fords still in use are very rare in this area now.

SW of Henffordd there is a line of very large oak trees, the footpath runs on the S side of them with a terraceway (although it looks to have been modified by modern use) then a field gate at SH64807210. If approaching from the opposite direction, there is a wicket gate slightly to the N of this, don’t use it because although it might seem to be the footpath there is no (legitimate) way out of the succeeding fields. Nothing evident behind Glyn farm, there is a footpath running SW of the building and on to Plas Nant which is featureless in itself, but presumably is a memory trace of the road, because the field boundary at SH64557180 has evidence of a ruined terraceway.

Nothing clear for next half mile (unless the boundary of Crymlyn Oaks wood has evidence, would need landowner permission; similarly in fields between Crymlyn and Gilfach). Then at SH63207142 there is a field boundary, with wicket gates and footpath on N, lower side. However, an earlier edition of OS shows the footpath on the southern side (but 1891 shows nothing), and there is a clear terraceway running parallel with the boundary here. After a break in the next field it is again seen W of Tan yr Allt at SH63907129, marked as a path on 1891 but not on modern maps, then there are near continuous boundaries through to Tan y Marian which are not accessible by public path. At SH62407089 the line crosses a by road which climbs very steeply up the hill to S through a small valley, and represents a drove road from Anglesey via Aber Ogwen through the Carneddau. At SH61987057 there is a clear terraceway by the field boundary, there used to be a house here according to 1838, which may be why the adjoining wood is still called Tan y Marian Bach on OS. A footpath comes up from Talybont onto line at SH61687022 and becomes a terraceway in edge of wood opening out to a walled track turning away from the alignment and going to a T junction at SH61626987. The track it meets seems to be a variant of the current minor road from Talybont to Llanllechid. There is then a FP over a footbridge over a stream at SH61606972 which is clearly not now on the line of any “road” but may be a memory trace? Coming up from the bridge to the present Llanllechid road there is a minor road opposite going to Tyddyn Isaf farm. What is now the accommodation road for Tan y Marian remains on the alignment, but of itself looks modern, and there is no obvious continuation on the opposite side of the Llanllechid road. This area needs more interpretation, the stream though small is quite a sharp drop and further W becomes marshy, which may help explain the lack of clarity.

At SH60976968 it looks as though a hollow way coming down to a marshy area has been “adopted” by a stream, then there is a track with an old quarry on S side going along field boundary to road at SH60816953, which is very nearly on the same alignment as that approaching Tan y Marian. Beyond the road is the well-known C15th manor house of Cochwillan (spelt as Cochwinllan on 1891), and on the far side of this at SH60626938 a blocked path goes into Coed Cochwillan, a wet hollow at first becoming a terraceway and taking a zig zag down through the wood to Afon Ogwen. The riverbanks are quite easily negotiable hereabouts, SH604693 but very steep to N & S, so it would be a good place to cross. Evidence there used to be a road and bridge crossing this stretch of river is provided by GAS XQS/1660/164, which is a presentment for repair of an unnamed bridge over the river Ogwen, flowing between Corrion (Cororion) and Bodvayo (Bodfaeo), situated on the road between Bangor and Conwey. Bodfaeo being the name of a mediaeval township encompassing Cochwillan.

On the far side of the river the access track to Lon Isaf could represent the line, then at SH60206911 we cross Ws road/Hen Durnpike from Capel Curig to Penrhyn Park, and a very narrow lane continues nearly on alignment with a small zigzag to get up a steep hillock at SH60076897. Just short of Cororion the lane turns S, and an accommodation road continues to the farm. Beyond this a terraceway can be seen at SH59526853, then a double boundary fence continues through Cororion Rough for nearly half a mile, both on 1891 and at present. After a slight gap and nearly on the same alignment at SH58956820 there is an access road to the house Pont Felin Hen (ie old mill bridge – there is an unnamed stream here). If you access the disused railway line, now a cycle route, between these two points, a wicket gate which would lead to the access road can be seen in the wall to the W, SH59046826, opposite on the E wall a corresponding access point has clearly been blocked with stone work, this strongly suggests that a right of way originally came through here.

From this point the B4366 is now the road leading directly to Caernarfon, but although the route is a direct one keeping to high ground, the actual road is a modern one based on a turnpike, last upgraded in the 1970s. The significance of the route in general terms is that it ignores Bangor, which has of course been a church site and subsequently a town since the C6th century (see variation of route above), and as M notes it is geographically well placed generally on higher ground between river valleys with commanding views. First however the Afon Cegin has to be crossed, the modern road does so near Groeslon roundabout SH56236685 but by this time the valley is so shallow that the crossing is imperceptible.

There does seem to be an alternative route on the northern side of the river represented by a disused track and right of way running from Tyn y Friddth SH58176841 (where it is now diverted from the front of the house N to the rear) past Tyn y Friddth cottage to Pen y Cefn at SH57436795 which has evidence of construction, side ditches, and some culverts. For this to be indicative of the Roman route we would have to postulate a crossing of the Afon Cegin at around SH585682, by way of a dogleg from the previous alignment. Topographically it would be a perfectly viable crossing, and once Tyn y Friddth is reached the advantage of higher ground as noted by M is gained. It also comes closer to the site of the now lost milestone found on Ty Coch farm (HH pp35-36). At Pen y Cefn the track ends on a minor road, there is a field boundary going straight on for about 600 metres which aligns well with the route now established for certain by aerial photography and excavation from Pentir switching station on to Caernarfon: most recently by excavation in advance of trenching a new pipeline at SH55596712, which I saw on 30th April 2021 when it was being excavated by Brython Archaeology.


1818 Ordnance survey drawings 2in/mile in British Library cat nos 301,305,306.

1838 Ordnance survey 1in/mile 1st ed

1891 Ordnance Survey 6in/mile & 25in/mile 1st edition 1891

GAS refers to Gwynedd Archive Service, Caernarfon

GATrefers to Gwynedd Archaeological trust records.

HH Edmund Hyde Hall, A Description of Caernarvonshire (1809-1811)

Hemp W. J. Y Cymrrodor vol33

M I. D. Margary, Roman Roads in Britain 1st edition

W Edmund Waddelove, The Roman Roads of North Wales, 1999. ISBN 0 9506803 1 1.

John Byde. Revision date 7th April 2022


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