At An Sliabh Riabhach in County Cork, a standing stone that was carefully recorded on the Ordnance Survey's six-inch map of 1842 had vanished entirely from subsequent editions, with neither the 1903 nor the 1940 revision showing any trace of it. In its place, or very nearly so, stands Coláiste Íosagáin, a former school whose construction almost certainly accounts for the stone's disappearance from both the landscape and the cartographic record.

Standing stones are among the most enigmatic survivals in the Irish countryside, single upright blocks of stone erected most commonly during the Bronze Age, though their precise purposes remain debated. Some marked boundaries, some may have had ritual significance, and others appear to have been associated with burial. The stone at An Sliabh Riabhach left no record beyond that single OS notation, which means everything about its original character, its height, its orientation, and any associated features, has to be considered unknown. What the 1842 map confirms is that it was present and recognisable as a monument at the time of the first systematic surveying of the Irish landscape. Sixty years later, it was gone, subsumed into a site that would go on to serve generations of local schoolchildren entirely unaware, most likely, of what lay beneath or had once stood nearby.