That trajectory, from unnoticed absence to ambiguous mound to invisible ground feature, tells a quiet story about how landscape features erode not just physically but cartographically.

The cairn sits on the high ground between Carrignabinnia and Slievecushnabinnia, precisely on the boundary where the townlands of Knocknagalty, Lyre, and Carrigeen Mountain converge. Boundary cairns, which are essentially deliberate accumulations of stone used to mark territorial limits on open upland, were practical rather than ceremonial features, though the line between the two was never entirely clear in an Irish context. This particular cairn does not appear at all on the Ordnance Survey Ireland six-inch map of 1840, suggesting it was either overlooked by surveyors or not yet regarded as worth recording. By the 1897 edition of the OSi twenty-five-inch map, however, it had been annotated as a 'Mound', a vague label that implies the surveyors could see something but were uncertain what to make of it. The Cassini edition of the six-inch map depicted it as a small circular mound. Two companion cairns recorded under the reference LI050-025002 and LI050-027 lie 120 metres to the south-west and 175 metres to the north-east respectively, suggesting the feature was part of a deliberate series of markers along the ridge. The record was compiled by Fiona Rooney and uploaded in November 2021.

By the time satellite imagery was examined, covering the period between 2011 and 2013, no surface remains were visible, a situation confirmed by later Google Earth orthoimages. The ridge itself is rough pasture, the kind of ground that discourages casual walking and obscures low earthworks beneath tussock grass and accumulated vegetation. Anyone hoping to locate the site precisely would need to cross open upland on the county boundary, using the recorded coordinates rather than any surviving surface feature as a guide. The companion cairns to the south-west and north-east may offer slightly more visible reference points, though the notes do not confirm their current condition either. What remains, in the end, is the boundary itself, still dividing the same three townlands it always did, even if the stones that once announced the fact have long since disappeared into the hillside.