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The Holyhead Road: the Ogwen Pass is a post-medieval and modern road crossing the Ogwen Pass in Wales. The route follows a historically significant line through upland terrain underlain by Ordovician felsic tuff, a volcanic rock formed during the ancient eruptions that shaped North Wales. The pass itself cuts through challenging mountainous country where bedrock becomes exposed at the surface, creating a natural corridor for transportation that has been used for centuries.
The road represents an important phase in Welsh transport development, serving as a key route linking the interior of Wales with the coast at Holyhead. Like other post-medieval roads in upland regions, it reflects contemporary improvements to communication networks and the infrastructure needs of the period. The route's path through the Ogwen Pass demonstrates how engineered routes adapted to the underlying geology, following lines of lesser gradient where possible through difficult terrain.
The monument is now protected by Cadw, the Welsh heritage conservation body, under reference CN338, recognising its significance as a surviving example of post-medieval highway infrastructure. The survival of the road in this remote mountain landscape provides evidence of historical communication patterns and the technical approaches to road-making in upland Wales during the development of improved national transport networks.
The Holyhead Road: the Ogwen Pass is a scheduled monument protected by Cadw under reference CN338. View the official record →
The Holyhead Road: the Ogwen Pass is a post-medieval and modern road crossing the Ogwen Pass in Wales. It is designated a Scheduled Ancient Monument by Cadw under reference CN338.
The Holyhead Road: the Ogwen Pass dates from the post medieval/modern period, and is classified as a road. It is one of over 32,000 scheduled monuments protected across the UK.
The Holyhead Road: the Ogwen Pass is a Scheduled Ancient Monument, legally protected by Cadw — the body responsible for designating and safeguarding heritage sites in Wales. The official designation reference is CN338.
Several scheduled monuments lie within 10 km, including Nant Ffrancon Anti-invasion Defences (0.5 km), Hut Circle Settlement at Nant Bochllwyd (1.3 km), Pen-y-Gwryd Pillboxes (5.3 km).
This page is just one thread. A full Aubrey report pulls together 13 strands of The Holyhead Road: the Ogwen Pass's history, each drawn from the record and mapped to the exact spot:
Every location is different. Not every section appears for every place, only what the historical record actually holds turns up in a report.
The Holyhead Road: the Ogwen Pass stands on Unnamed Extrusive Rocks, Ordovician, bedrock that formed in the Ordovician. The rock here is felsic tuff.