A ringfort, sometimes called a rath, is an enclosed farmstead of the early medieval period, typically defined by one or more circular earthen banks and an outer ditch; thousands were built across Ireland, and thousands have since been ploughed, grazed, or simply worn away by time.

By 1842, when the Ordnance Survey produced its first large-scale six-inch maps of Ireland, this particular enclosure was still clear enough to be recorded as a hachured circle roughly thirty metres in diameter. What the cartographers captured has since largely vanished. The southern quadrant remains as a low scarp, running from south-east to south-west with a height of around 0.4 metres, and a depression of similar depth just outside it to the south-east may represent what was once the fosse, the outer ditch that would have reinforced the bank. To the north and east, the field boundaries have absorbed or obscured any trace. A researcher named Bowman, writing in 1934, recorded two such levelled single-ramparted forts in this immediate area, one on land belonging to a Daniel Foley and another on land held by a D. Kinneally, measuring 31 and 35 yards in diameter respectively. The Kilberrihert example appears to be one of that pair, which means the site was already recognised as an archaeological feature nearly a century ago, even as agricultural activity continued to reduce it.

The site sits in pasture, which is both the reason it has survived at all and the reason so little of it is legible. Grazing land is gentler on buried archaeology than tillage, but it also means the remaining earthworks are subtle enough to be easy to miss. The south quadrant, visible as a slightly raised area in the northern corner of the field, is best observed in low winter light, when raking shadows bring low scarps into relief in a way that summer grass growth tends to disguise.