The feature is not marked as anything significant on the landscape, and at ground level it barely announces itself: a scarp no more than a metre high at its southern edge, tapering to almost nothing at the north. Yet from satellite imagery, the shape resolves into something deliberate, a suboval enclosure roughly 60 metres east to west and 52 metres north to south, with a possible entrance just a metre wide on its western side, a large stone standing at the east of the gap. A fosse, or defensive ditch, of around five metres in width is visible from the air but has entirely disappeared at ground level, absorbed into the pasture over centuries.

The enclosure was first noticed not during a field survey but by Emmet Byrnes of the Forest Service, studying Bing satellite imagery and Ordnance Survey orthophotography. That kind of discovery is increasingly common in Irish archaeology, where aerial and digital tools reveal cropmarks and earthworks that centuries of farming have rendered invisible to anyone simply walking the land. The OS six-inch map of 1840 names the surrounding area 'Cloonacullaun', while by the 1920 edition the same ground is labelled 'Garden Hill', a shift in placename that may reflect the enclosure's proximity to the walled garden of Ballynahinch House, which lies roughly 70 metres to the southwest. Whether the 'Garden Hill' name preserves some folk memory of the earthwork's shape, or simply refers to the nearby walled garden, is an open question. A mature field boundary running north-northwest to south-southeast along the eastern side of the platform suggests the enclosure's outline has, at least in part, been incorporated into the later field system, its edges quietly repurposed without anyone necessarily recognising what lay beneath. The monument was subsequently reported to the National Monuments Service by Séamus Ó Murchú.