Something sits in the scrub at Ballynaclogh that the Ordnance Survey cartographers of the 1840s thought worth marking, yet which has since become effectively invisible at ground level. The feature they recorded was a roughly square enclosure, approximately 25 metres on each side, set on a small hill just south of a rock outcrop called Carrickrower. By the time the 25-inch OS map was produced, the same feature was being described differently, as an arc of an enclosure running southeast to northwest with a circumference of around 30 metres. That the two surveys describe what appears to be the same site in noticeably different terms hints at how much the feature had already degraded between one survey generation and the next.

What makes the site quietly peculiar is a detail of its geography. In both map editions, the enclosure is noted as transgressing the townland boundary, meaning it straddles the administrative line between two distinct territorial units. Townland boundaries in Ireland are ancient in origin, many of them preserving land divisions that predate any surviving written record, so a monument that cuts across one suggests it may itself be of considerable age, possibly predating the boundary, or at the very least that it was significant enough in its original use to ignore such divisions. The site sits within a cluster of related features: a second enclosure lies roughly 20 metres to the south, and a third approximately 60 metres to the west-southwest, which raises the possibility that this small hilltop was once part of a more extensive arrangement of enclosed spaces, their original function now uncertain.