There is no ditch to step across, no earthen bank to climb, no stone wall to trace with a hand. The ground gives nothing away. The enclosure exists, in any meaningful sense, only as a ghost pressed into the soil, and it was an aerial photograph that first revealed it, showing up as a cropmark, the faint differential in how vegetation grows above buried or disturbed ground that can betray the outline of ancient structures long since levelled flat.

Cropmarks of this kind have been one of archaeology's more quietly remarkable tools, allowing features that have vanished entirely at ground level to reappear, briefly, when seen from above under the right conditions of drought or low sun. The enclosure at Ballynanerroon More was recorded from aerial photography held by the Geological Survey of Ireland, and its circular form, at around 37 metres in diameter, places it broadly within the tradition of enclosed settlement sites found across Ireland, though without excavation it is impossible to say more about its date or function. A local archaeological survey of the Ballinrobe district, covering the Lough Mask and Lough Carra area and compiled by D. Lavelle in 1994, catalogued it among the area's sites, preserving at least a documentary trace of something the landscape itself has otherwise swallowed entirely.