It is a bullaun stone, a type of rounded or flat boulder bearing one or more cup-shaped depressions ground into its surface, and this particular example measures roughly half a metre in length with a single basin nearly thirty centimetres across and fourteen centimetres deep. Bullaun stones are found at monastic and sacred sites across Ireland, and while their precise original function remains a matter of debate, they are associated with ritual use, possibly for grinding, for holding water, or for acts of devotion and cursing alike. Their placement at thresholds, as here, adds another layer of quiet ambiguity.

The site at Bola Beg sits on a gentle rise on the northern bank of a stream running west-northwest to east-southeast, roughly forty metres to the south. The antiquarian John O'Donovan, writing around 1840, recorded that this was an early monastic foundation established by a St Colman in the seventh century, a detail preserved in later scholarship through O'Flanagan's 1933 compilation of O'Donovan's letters. The church itself stands within an oval graveyard defined by an earthen bank, an enclosure form typical of early Irish monastic settlements, where the curved boundary often predates and outlasts the buildings it once protected. The combination of that enclosure, the church ruin, and the bullaun stone lodged in its doorway makes Bola Beg a quietly layered place, where the physical remnants of seventh-century religious life are still legible in the landscape.