Roman Roads


Canovium to Segontium


                     As of July 2002 the grid references are derived from 1:25000 and memory, and will therefore need some  refinement.



1795   Evans J - Map of North Wales (ca 1795)

1818   Ordnance survey drawing 2in/mile in British Library cat no 306. Photocopy available at GAS.

1838   Ordnance survey 1in/mile 1st ed as reprinted Harley/Oliver, Old Series Ordnance Survey Maps, vol 6 (ISBN 0903541440)

1891   Ordnance Survey 6in/mile 1st edition 1891, as read

A        William Ashton, The Evolution of a Coastline (1920) (Caernarfon public library)

AA      Bassett T. M & Davies B. L. edd, Atlas of Caernarvonshire (1977)

D        Dodd A. H, Arch Cambrensis Vol V  (1925)          Roads of North Wales 1750-1850 p.130

E        Rev J Evans, A Tour through part of North Wales (1798) (Caernarfon public library)

GAS    refers to Gwynedd Archive Service, Caernarfon

GAT   refers to Gwynedd Archaeological trust records.

H        J Hucks – A pedestrian tour through North Wales (1795 reprinted/edited 1979) (Caernarfon public library)

HH      Edmund Hyde Hall, A Description of Caernarvonshire (1809-1811) ed Emyr Gwynne Jones 1952 (Caernarfon public library)

M       I. D. Margary, Roman Roads in Britain, vol 2, 1st ed 1957, pp81-82.

N        North F J, Sunken cities; some legends of the coast and lakes of Wales 1957

R        Royal Commission on Ancient & Historical Monuments (Wales) Caernarvonshire vol i 

S        J A Steers, The coastline of England and Wales.

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




Most recent description is M,  with accompanying references. (Pagination is of original 1957 edition, since I own this but do not have access to the 1973 revision). The initial reference appears to be Archaeologia Cambrensis vol 1 p 72, referred to by Codrington, whose description is very brief. It has always been known where it passes through Bwlch y Ddeufaen at the northern end of the Carneddau, with accompanying milestones and other prehistoric monuments nearby. The topography is such that I doubt whether the Romans were the first to use the pass. This route will also presumably have become the pilgrim way to Bardsey Island which is described by Waddelove further on, south of Caernarfon, at least until the crossing and town at Conwy were created by Edward I in 1282. However some more detailed description seems in order, and once off the mountain the course is not known except by hypothesis.


The same route is used by National Grid powerlines established (when?), and the wide well established track that is popularly referred to as the Roman road was presumably utilized, and probably upgraded, for their construction. Travelling west up to and from the top of the pass there are however numerous places where an older route is visible to one side or the other of this track; however, it is not of itself a C20th creation, since it appears on 1891, and the route was included in the turnpike Act of 1777, and possibly some work undertaken, (D, HH p37 “rough bridle road” and others). The road fords a stream at 7030  7207 by way of an upstream zigzag, and W of this the earlier course is marked by a hollow on N side of present track. (still shown as a separate right of way on current 1:25000). After a second ford at 6992 7222 the modern road bears to the south uphill, crossing the shoulder of Yr Orsedd 6930 7224. 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 6921 7255. 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 crest seems significant because it an excellent aiming point from Gorddinog below, a clear saddle in the profile of the spur of the mountain. This is where Margary’s text is confusing, because he refers to a narrow terrace zigzagging down to Gorddinog. In fact the route to that point is straight, it is the presumably later version taking a short cut to Bont Newydd and then Aber which has a series of well defined zigzags. Bont Newydd is already so named in 1652 (GAS XQS1652/156, where the road is called “hwylfa gogvfryn”).  I think he must have confused Gorddinog with Aber. The four milestones found on or near the Gorddinog route, GAT record 4066 at SH67907275 and in Coed Gorddinog [latest revision of Roman Frontier in Wales but not apparently RCAMW database], plus its very clear military advantage going down a spur of the mountain with extensive views, seems conclusive enough. [A p209 envisages this road crossing what is now the Lavan Sands, with a ferry crossing to Penmon and a road across northern Anglesey continuing to Parys Mountain. He describes Penmon as “directly opposite” although Beaumaris answers that description better. For modern critiques of his general hypothesis about a C6th inundation of “Llys Helig” see N & S.  One might assume that after the primary military use, whether during the Roman period or later, the short cut became the accepted means of travel.  However, from here to the beginning of the modern tarmac road at 6760 7160 the diversion seems to have two stages, because apart from the modern road going over at 6930 7224 as mentioned above, there is a narrow hollow track dropping from the crest at 6921 7255 to 6892 7212, where it crosses the modern track obliquely and does indeed continue as a clear, very narrow, slightly hollow terrace ending in a series of zig zags coming down to the road end at 6760 7160. This line is littered with cairns, enclosures etc of uncertain date, so maybe it is not necessarily later. The modern track takes an easier more circuitous route down to the road end.  There has also been a water pipeline laid across the hillside roughly parallel with and between the two routes, which throws up superficial evidence of a “terrace”.


Returning to the direct route, there is a track continuing the line down from the spur although it curves away N at 7265 6890. 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 zigzag as shown on both 1891 and current 1:25000. A wall comes onto line at 6880 7270, and the route is marked as a footpath on 1891 and right of way on 1:25000, and as a road throughout on 1838, although noone seems to walk on it now, due no doubt to its inaccessibility further down. From 6835 7285 on it develops as a very wide deep hollow way in which rock has often been dumped, petering out at 6795 7305. 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. Another right of way veers to N, which I have not explored. The wall goes straight on to a T junction at 6786 7330, 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 6775 7327 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 6760 7322.  This runs out into the field where there are no visible traces. 


However one regards Ashton’s hypothesis, there must have been a road turning SW at Gorddinog because 2 further milestones have been discovered in the wood [recover details from Roman Frontier…] The only public access is on the modern track which zigzags up from Tan y Clogwyn cottages, but 1891 shows tracks in the wood, and 1838 shows the present byroad passing S of the cottages and on to Aber, which has disappeared by 1891. This seems to resume as a terraceway at Pen y Bryn 6580 7280, and a little further a prominent causeway can be seen in the field approaching the river. This is the bridge abutment described in R no 8, with no comment as to date. Need landowner’s permission to do more investigation on this stretch. There is a motte and bailey at Aber, nb Ws comments about how often they are sited by Roman roads.


The next evidence is somewhat to SE of this alignment, approaching the farm Henffordd 6522 7232. There is a footpath leaving the byroad to Bont Newydd (which itself is the continuation of the later diversion described above) at 6578 7248 (not the track going straight up the shoulder of the hill) and curving round the hillside to the farm. At 6552 7255 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 general principle seems to be that the line runs in the angle between the mountainside and the coastal plain; it 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 S, which may also be of significance.


Slightly further down the plain is the byroad from Aber church, which runs to Crymlyn (marked here by 1891 as Roman Road), then below the former Penrhyn Estate stables at Tyn yr Hendre, St. Cross church, down a hollow way at 6065 7085 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 5882 7115, with a hollow way continuing up the hill, then a minor road on Maesgeirchen estate and a metalled track over Bangor mountain and down to the city. Presumably this is the pilgrim/medieval route again. The by road and ford at the Cegin at 5867 7065 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 6480 7210. 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 6455 7180 has evidence of a ruined terraceway.


Nothing clear for next half mile (unless the boundary of Crymlyn Oaks wood has evidence, again would need landowner permission; similarly in fields between Crymlyn and Gilfach). Then at 6320 7142 there is a field boundary, with wicket gates and footpath on N, lower side. However, an earlier edition of 1:25000 shows the footpath on the southern side (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 6390 7129, 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 6240 7090 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. [What is the significance of Cae Gwilym Du in Gothic script on 1891]. At 6198 7057 there is a clear terraceway by the field boundary [probably clear enough to section?], 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 1:25000. Remaining boundary walls – need permission for access.


A footpath comes up from Talybont onto line at 6168 7022 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 6162 6987. 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 6160 6972 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 6097 6968 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 6082 6956, 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 6062 6938  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, 604694, but very steep to N & S, so it would be a good place to cr1891s. Evidence there used to be a road and bridge cr1891sing 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 (AA p72, Journal of Welsh Ecclesiastical History 5.54 via, refs in Bangor university archives Penrhyn Castle papers GB 0222/Bangor 57)


On the far side of the river the access track to Lon Isaf could represent the line, then at 6020 6921 we cr1891s 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 6007 6897. Just short of Cororion the lane turns S, and an accommodation road continues to the farm. Beyond this a terraceway can be seen at 5960 6857, then a double boundary fence continues through Cororion Rough for nearly half a mile, both on 1891 and at present. There is no public access here, further investigation is needed. After a slight gap and nearly on the same alignment at 5895 6820 there is an access road to the house Pont Felin Hen (?name). 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 , 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 5620 6688 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 5815 6845 (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 5743 6795 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 585683, by way of a dogleg from the previous alignment. There is nothing obvious to be seen in the fields from a distance, but a closer investigation would require landowner permission. 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 yards, but there is now a long gap in field evidence here although access to private land might clarify the situation. There looks to have been more cultivation W of the Afon Cegin than previously, which will have degraded any evidence. There is the very slightest hint of a swelling on the alignment where a field boundary crosses it obliquely at 5598 6706. M records evidence of a road being discovered in the grounds of the former Rectory at Llandeiniolen which is at 5415 6605 and beyond this there is a rough alignment of footpaths starting at 5404 6585 through to 5308 6502, at which point there is a length of long disused track with evidence of side ditches. It may be this stretch that is described in C18th writers, eg E p164, “the remains of a Roman road are still visible from this place [Segontium] to Dinorwig”  [ie the Iron Age hill fort of Dinas Dinorwig at 550653, not the modern village of that name] and E p141 “A similar [road to Sarn Helen] is discoverable at Y Gym Wynas in Caernarvon”

Beyond this a minor road seems to represent an echo of the route although not I would think the actual line; it appears on 1795 – access to the fields to the N might reveal something. The final stretch M and W seems more secure, although W of course thinks the route to the NE runs further to the N to come in to his projected Roman base in Penrhyn Park. It may not necessarily be a case of “either/or”, if the route from Rhyn Park to Penrhyn can be seen as the early invasion route to Anglesey, this road running at 90 degrees is more obviously related to the long term axis of the legionary base at Chester and the forts at Canovium and Segontium




Copyright John Byde.    Revision date 28 February 2004