The great stone hillfort which crowns the scree-strewn summit of Mynydd Carn-ingli remains one of Pembrokeshire's great mysteries. The stone-built remains of ramparts, enclosures, huts and fields clearly have their origins in prehistory but, as yet, no excavations have shed light on the development of one of the largest hillforts in west Wales. Mynydd Carn-ingli is first recorded in the twelfth century as Mons Angleorum, reputedly the place where St Brynach met and discoursed with angels. It is not unusual that such a wild and remote spot should have attracted its fair share of visitors over the years. In his tour of Pembrokeshire, Fenton described it thus:

'Carn Englyn? affords a most pleasing prospect of the bays of Newport and Fishguard,?. Its summit, like that of most of the heights in this district, bears marks of early habitation, enclosures of various forms occurring amongst the wildest and most broken parts of it..'

The first detailed archaeological survey of the multitude of stone enclosures was published by A H A Hogg in 1973, who was able to establish many aspects about the site which make it unusual in Welsh prehistory. The natural summit crags of Carn-ingli are enclosed by a long fortification formed of high, rough-built defensive walls. The earliest phases appear to be three conjoined enclosures on the highest point, which are probably the result of multiple periods of occupation and enlargement. The fourth and largest enclosure extends to the north onto lower ground and is crowded with stone-built huts and pounds and even the remains of an old street or track. In all, the ramparts are pierced by twelve gateways, some through the cross walls which divide the successive enclosures, and some through the main outer walls. This is a very high number of vulnerable openings to defend if we assume the structure is an Iron Age hillfort, and it may be that parts of Carn-ingli date back far earlier, to the Neolithic or Bronze Age. Another remarkable feature about the hilltop is the number of small pounds and platforms built on the slopes surrounding the fort, thought by Hogg to have been designed in prehistory to cultivate crops in the thin, stony soils.

Some researchers have suggested that parts of Carn-ingli were occupied during the early medieval period, but Hogg cited the widespread, apparently deliberate, throwing down of walls and ramparts across the hillfort as evidence for systematic destruction by Roman invaders in the aftermath of the conquest of Wales. Such a dramatic interpretation, placing the Roman legions on the slopes of Carn-ingli in an attack on its inhabitants, might be questioned today.

All around Carn-ingli hillfort, particularly on the lower hillslopes to the north and west, survives a rich and well-preserved landscape of old field boundaries, clearance cairns, round huts and farmsteads which represents one of the great surviving prehistoric landscapes of southern Britain, . Uunploughed in recent centuries., but enclosed and improved along its northern fringes by historic fields radiating from Newport and Dinas Cross, aAerial photography is a particularly powerful way to show the dense surviving remains of a prehistoric hillside as it was farmed and settled, probably dating to the Bronze and Iron Ages. Doctoral research by Alastair Pearson of the University of Portsmouth in the 1980s and 1990s suggested that many of these fields and worn trackways had their origins in the Bronze Age.

T. Driver, RCAHMW, 18 December 2009.