It carries no inscription, no carved cross, no ornament of any kind; just a plain, uneven stone measuring roughly 1.25 metres long and 0.66 metres wide, placed in the south-eastern corner of the enclosure. Its very anonymity is what makes it quietly interesting. Most early medieval grave markers on sites like this were carved with at least a simple cross or an inscription, and their absence here raises questions that the stone itself declines to answer.

When the scholar R.A.S. Macalister surveyed and mapped the Saint's graveyard on Inis Cealtra between 1916 and 1917, he noted this slab among the others but left it unnumbered on his plan, marking it only as plain. That act of non-classification is telling. Macalister was meticulous about recording inscribed and decorated stones, and the numbered slabs on his plan tend to be those with something legible to say. This one had nothing, and so it sat at the edge of the record, 4.7 metres from the east wall and 6.34 metres from the south wall, precisely located but otherwise unaccounted for. Whether it marks the grave of someone buried in the early medieval period, or was placed later, or was perhaps a reused stone, remains unclear.