It is easy to overlook. But a bullaun stone, a rock bearing one or more cup-shaped depressions ground into its surface, often through long ritual use, is one of the more quietly persistent features of early Christian Ireland, and this one sits inside one of the more complete early monastic enclosures in the country.

Illauntannig is the largest of the Magharee Islands, a scatter of low islands off the northern tip of the peninsula dividing Brandon Bay and Tralee Bay in County Kerry. The island carries an early Christian settlement enclosed within a substantial cashel wall, a cashel being a stone enclosure of the kind that served both to define and protect a monastic community. Inside that wall survives a remarkable concentration of features: two small oratories, three beehive huts (the corbelled dry-stone cells associated with early Irish monasticism), a souterrain and wall-chamber, three leachts, a burial ground, a stone cross, and three cross-slabs. A hand-bell and fragments of five quern-stones have also been found within the enclosure. The bullaun at the foot of the cross is one of two on the island; a second lies roughly a hundred metres to the south, at the edge of the sea. Associated remains on the nearby promontory of Reennafardarrig, including a hut-site, old field walls, and a reputed cross-inscribed boulder, may extend the footprint of the same early settlement.