|Northern entrance which leads to the fort extension.|
|This photo shows the outer wall, and also demonstrates how the fort relates to the one at Dinllaen.|
|Circular hut foundations.|
The site occupies 5 acres. The foundation walls of the 150 circular huts that made up the village can still be clearly seen, surrounded by the outer, protective stonewalls that in places are still 3 metres high. To the north there is an extension to the outer wall which may have guarded a cattle enclosure. The huts are between 3 to 8 metres in diameter and would have been the foundation for conical roofs of timber and reed. On the north side there are some larger rectangular structures-perhaps an aristocratic quarter. There appears to have been an open courtyard in the middle. The fort is believed to have been built around 100 B.C and occupied during the Roman Era until 400 A.D. However, the Cairn at the hill summit is much older and dates back to the Bronze Age. Opinions are divided as to the reasons for the fort’s existence 450 metres high on a windswept and inhospitable hill, amidst poor farmland and with no water supply within the fort [there is a spring just outside the postern gate but it's hard to imagine permanent occupation through the winter].
One theory is that it was one of a series of hillforts that were occupied for short periods only (but in considerable strength) by a mobile army of Celtic/Gaelic people coming from what is now Leinster in Ireland.Others argue that the positioning of hillforts across North Wales suggest some kind of local tribal groupings and that they may even have been more for show than war. These military groups were possibly what often passed for government beyond the outer fringes of the Roman Empire. No remains of substantial Roman buildings have been found further West than Segontium (Caernarfon) There was a watch tower on part of the Dinas Dinlle mound which related to one on Holyhead Mountain and the remains of a Roman marching camp at Derwydd-Bach(477454) which can be seen from Tre’r Ceiri, and there was a Roman Auxiliary fort Pen Llystyn, on the opposite side of the A487 adjacent to the camp, that was occupied from AD 80 to 130 ish. It's now been quarried away apart from a little bit of the rampart].
It is just this side of the present main road, the A487, directly due West. The “celtic” army on your side of the border would have descended on the area, occupied the fort for a few days, terrified the locals, dispensed justice and mopped up any food surplus, and then moved on leaving perhaps a skeleton staff to maintain the fort and to maintain what the Mafia would today call “Respect” and an orderly border with the Romans. There is no evidence for any slighting or Roman occupation of Tre'r Ceiri and there was definitely additional building during the Roman period. Also Roman pottery from the site shows that they were trading with them. I suspect that after an initial bloody conflict the Romans came to some accommodation with the local tribes. After the conquest in about AD78 they started withdrawing troops towards the end of the century leaving only a small garrison, suggesting a peaceful but under the thumb type coexistence.