A bullaun stone, which is a boulder or slab bearing one or more cup-like hollows ground into its upper surface, this particular example is modest in size, roughly forty-six centimetres across and only twenty centimetres high, with a circular hollow about twenty-five centimetres in diameter worn so deeply into it that it has broken through the base at one side. Bullauns are found across Ireland, often close to early ecclesiastical sites or holy wells, and their precise original function remains debated; theories range from grinding or processing plant material to ritual use connected with cursing or healing. This one sits quietly on the east side of the road, paired with the well beside it.

What distinguishes the Cappanagraun stone is a detail recorded by Patrick Logan in 1980. At some point, the stone was removed and built into a wall. The following morning, it was back at the well. Logan does not elaborate on who moved it, or who found it returned, but the pattern he describes is familiar from Irish folk tradition, in which certain stones, trees, and water sources are understood to resist displacement and find their own way home overnight. The stone does not appear on the six-inch Ordnance Survey maps of either 1842 or 1904, which may simply mean it was not noticed by surveyors, or that it had not yet been recognised as a distinct object of interest at those dates.