It bears no inscription, no carving, no cross, nothing that might identify who lies beneath it or when they were placed there. It is simply a flat, recumbent slab of stone, measuring just over a metre in length and nearly three quarters of a metre wide, lying in the northwest corner of the Saint's graveyard.

When the antiquarian R. A. S. Macalister surveyed and drew up a plan of the graveyard in 1916 and 1917, he included this slab in his illustration but gave it no number, a telling omission in a survey that otherwise catalogued its subjects with some care. Whether that reflected uncertainty about the slab's age, its lack of distinguishing features, or simply the limits of what could be known about it, is not recorded. Its position is precise enough: 22.3 metres from the southern wall and 1.9 metres from the western wall of the graveyard. That level of specificity, coordinates without context, is in some ways the most curious thing about it. The slab is known exactly where it is, and almost nothing else about it is known at all.