Carved into its upper surface are five evenly formed bowl-shaped hollows, each around thirty centimetres across and twelve centimetres deep, now submerged beneath the current. The stone measures two and a half metres in length and sits quietly on the riverbed, doing what it has presumably done for centuries.

The hollows identify it as a bullaun stone, a type of carved stone found widely across early medieval Ireland, typically associated with monastic or sacred sites. The bowls were ground or pecked into flat rock surfaces, and while their precise original function is debated, they are closely associated with religious practice, healing rituals, and the accumulation of rainwater thought to carry curative properties. The proximity of this example to Cong Abbey, a twelfth-century Augustinian foundation and one of the more significant ecclesiastical sites in Connacht, is unlikely to be coincidental. Whether it predates the abbey or was in use alongside it is not recorded, but the association between bullaun stones and early Irish monastic communities is well established. What makes this particular example unusual is simply where it ended up: not beside a church wall or in a field, but underwater, on a riverbed, still more or less intact.