The problem is that nobody has been able to get close enough to say very much about them. Dense furze, the low prickly shrub that colonises rough ground with impressive determination, has made the hilltop effectively inaccessible, and no archaeological features have been confirmed on the ground. The site may be nothing more than a natural glacial landform. It may be rather more than that.

The hill in question sits on an esker ridge, one of the long sinuous gravel ridges deposited across the Irish midlands by meltwater rivers running beneath retreating glaciers at the end of the last Ice Age. Eskers were significant features in early medieval Ireland, often used as routeways through boggy terrain, and the landscape around Clonmacnoise, the great monastic site on the Shannon a few kilometres to the west, is particularly rich in them. It was during an archaeological survey of that wider region in 1987 that T. McDonald first flagged this site, describing a group of cairns at the foot of The Pinnacles that appeared to encircle the hill. Whether those cairns are prehistoric monuments deliberately placed on a prominent natural feature, or simply field clearance material, or something else entirely, has never been established. The furze has not made that easy to resolve.