A bullaun is essentially a boulder or outcrop of rock into which one or more rounded depressions have been ground, producing a bowl-like hollow. These hollows are found across Ireland, often near early ecclesiastical sites, and their exact purpose remains a matter of debate. Some scholars associate them with grinding or processing, others with ritual use, and in folk tradition the water that collects in them is frequently regarded as having curative properties.

The Ballynakilly stone sits within south-west Kerry, a part of the country with a dense and varied archaeological record stretching from the prehistoric into the early medieval period. The region was catalogued in the Archaeological Inventory of County Kerry, compiled by Muiris O'Sullivan and John Sheehan and published in 1996, which remains a key reference for understanding the distribution and character of monuments across this corner of Munster. The bullaun at Ballynakilly is recorded within that volume, though the surviving description is brief, reflecting how many such stones were noted and mapped without extensive excavation or documentary context to draw upon.