It is a bullaun, a term for a rounded or sub-rectangular rock bearing one or more deliberately worked depressions, and this one is modest by any measure: roughly 25 by 30 centimetres, with a shallow bowl at its centre no wider than a cupped hand. What makes it remarkable is not its size but what fills that bowl. Coins, rosary beads, a cross, and small religious statues have accumulated there, left by people who still regard the stone as a site of prayer and petition.

Bullaun stones are found across Ireland, often associated with early medieval ecclesiastical sites, and their original purpose remains genuinely uncertain. Some may have been used for grinding herbs or pigments; others appear always to have carried a ritual or votive function. At Durrus, the stone has been deliberately incorporated into the ruined church wall rather than left loose in the landscape, which suggests it was considered significant enough to preserve even as the building around it fell into decline. Immediately beside it, and used for offerings in the same way, is a fragment of cranium, a human skull bone. The pairing of the ancient bullaun with this relic, both receiving coins and objects from visitors, points to a layered kind of devotion that folds early Christian, post-Reformation, and folk practice into a single small space without any apparent contradiction.