What makes it worth a second look is the shallow basin worn or carved into its upper face, the defining feature of what is known as a bullaun stone. Bullauns are among the more enigmatic objects in the Irish early medieval landscape; hollowed stones found near churches, monasteries, and holy sites, their precise function remains debated, with suggestions ranging from liturgical use to the grinding of pigments or grain. This particular example is a fragment rather than a complete stone, measuring roughly 46 by 42 centimetres, with a basin approximately 28 centimetres long, 24 centimetres wide, and only 6 centimetres deep.

The clochan beside which it rests is itself a structure of some age, a drystone beehive hut of the kind associated with early Christian monastic settlement in the west of Ireland. Writing in 1869, the geologist and antiquarian G.H. Kinahan proposed that the bullaun had not always stood here, suggesting it may originally have come from a site known as Temple-an-chealhrairaluinn, a placename that hints at an ecclesiastical origin. Whether it was moved deliberately, or simply ended up beside the clochan through some later rearrangement of the landscape, is not recorded. The stone's broken condition adds another layer of uncertainty; it is unclear when or how it was fractured, or whether the complete stone once held a deeper or differently shaped basin.