The fence follows a townland boundary, one of those administrative divisions fossilised into the landscape over centuries, and it cuts across the rath with a kind of indifference that is quietly telling. The ringfort has outlasted its original purpose by more than a millennium, only to find itself partitioned by a more recent human convenience.

Raths, the earthen ringforts that pepper the Irish countryside in their thousands, were typically built during the early medieval period, roughly between the fifth and twelfth centuries, and served as enclosed farmsteads for farming families of some local standing. This one at Ballygreighan sits on a low rise along an east-west ridge, a position that would have given its inhabitants a modest but useful vantage over the surrounding pasture. The enclosure is roughly circular, about twenty-two metres across, and surrounded by an earthen bank three metres wide. The bank still stands to a height of between 1.6 and 1.7 metres on its exterior face, though the eastern half has been considerably reduced and partly levelled over time. What may have been the original entrance survives as a gap of about 1.4 metres on the south-western side of the bank. There are also hints of an internal stone kerb, a feature that would have lined the inner edge of the bank, and a narrow line of stones still protrudes through the sod and runs east-west across the southern portion of the interior. Whether those stones represent a wall footing, a path, or something else entirely is not entirely clear, which is part of what makes the place interesting to consider.