SNPA Strapline

Snowdonia from the Air

Llyn Trawsfynydd

Snowdonia from the Air

The Roman Occupation

The inhabitants of north-west Wales were known to the Romans as the Ordovices. Tacitus records a number of campaigns against them in the eighteen years before their final conquest by Agricola. Evidence of these campaigns can perhaps be seen in the large marching camps now known from near Llanfor, Bryncir, Tomen y Mur and at Pen y Gwryd. After the conquest in 77-8 AD a series of forts was constructed at carefully chosen strategic locations around Eryri, controlling the main routes through the mountains and all linked by a road system. The conquest would have resulted in significant political, economic and social changes and the fort-building programme represented a considerable investment of manpower and materials.

Most of these forts were in use for perhaps only seventy years but Segontium, on the low hill above modern Caernarfon, remained as an administrative centre until the very end of the fourth century. After the initial phase of conquest and military occupation, the native communities would have prospered under the economic influence of the Roman administration. From the second century onwards there is evidence for the development of a distinctive type of native settlement, known as enclosed hut-groups. Excavations at the settlement at Graianog, near Bryncir, showed that large quantities of grain were being grown and that the inhabitants had a relatively sophisticated life-style, using consumer goods of Roman taste and manufacture. Even some of the large hillforts continued to be inhabited and the occupants used Roman pottery. At Braich y Ddinas hillfort, Penmaenmawr, coinage was also in circulation, indicating a degree of integration into the Roman economic system.

Although the locations of all the main Roman forts are known, new discoveries continue to be made, including marching camps, practice camps, watch towers, tile kilns and, of course, additional details of the road system. Because of the distinctive shape and regularity of the Roman military remains they are particularly suitable for recognition by aerial photography, even when they have been denuded by ploughing.

Tomen y Mur, Trawsfynydd

Tomen y Mur, Trawsfynydd © RCAHM 945119-48

One of the most interesting archaeological areas in Snowdonia is the complex of Roman and other remains around Tomen y Mur, near Trawsfynydd. The fort was first built in timber and about 30 years later it was reduced in size and rebuilt in stone. The fort occupies a low rise with commanding views of the surrounding countryside and the same strategic position was used by the Normans for their earthwork castle. There is a tradition, based on the Mabinogion tale of Math fab Mathonwy, that this was also the site of a Dark Age llys, for which there is not yet any archaeological confirmation. The National Park Authority now has a management agreement with the owner of Tomen y Mur, which is a rewarding site to visit. A selection of the stone wall has been reconstructed to its full height, with a reproduction of one of the centurial stones found on the site.

Tomen y Mur, Trawsfynydd

A: Roman fort. B: Norman motte overlying gate of second phase rampart. C: SE gate of fort. D: Bath-house and mansio. E: Bridge abutment, for road to cross stream. F: Parade ground. G: later ?post-Medieval settlement site. H: The amphitheatre. J: water leat to the bathhouse. K: leat from Llyn yr Oerfel to the fort. The final section would have been a wooden aqueduct. L: Medieval leat. M: Medieval boundary bank and ditch. N: Roman road to north. Q: Road to west. R: Old road. T: 19th century tramway to Braich Ddu quarry.