The upper piece is a bullaun, one of those roughly shaped rocks bearing a smooth, bowl-like hollow worn or carved into its surface, which are found at early medieval religious and ritual sites across Ireland. The hollow here is about fifteen centimetres across and four centimetres deep, modest by any measure. What gives the arrangement its particular strangeness is what sits beneath it: an upright architectural fragment decorated with barley twist carving, the kind of spiral rope-like stonework more associated with church doorways and manor houses than with garden corners.

The two objects do not obviously belong together, and according to local knowledge, they were never meant to. The architectural fragment, which stands roughly half a metre tall and measures about eighteen centimetres wide, is said to have been brought to this site from King's Island in Limerick city. King's Island is the old urban core of Limerick, home to St Mary's Cathedral and the remains of King John's Castle, and its medieval stonework has had a complicated afterlife as buildings were altered, demolished, or stripped over the centuries. How or when this particular carved piece made the journey to Garranbane is not recorded, but its presence beneath the bullaun suggests someone, at some point, found a logic in pairing them, or simply placed one convenient surface on top of another.

The bullaun itself is small and irregular, measuring roughly thirty-two centimetres by twenty-four centimetres, and would be easy to overlook if you did not know to look for it. Access to the site depends on the status of the walled garden and its surrounding grounds, so it is worth making local enquiries before visiting. The garden setting means the stone is sheltered rather than exposed, and the barley twist decoration on the fragment beneath it is worth examining closely once you are there, as carved surface ornament of that quality is not something you expect to find used as a plinth in a garden corner.