These are cupmarks, one of the most ancient and least understood forms of rock art found across Ireland and Britain, produced by sustained pecking or grinding with a harder stone. Nobody knows with certainty what they meant to the people who made them, which is part of what makes them quietly unsettling to look at. The stone itself is modest in scale, roughly 95 centimetres long and just 28 centimetres wide, lying flat so that its marked upper surface faces the sky.

The cupmarks range from three to eight centimetres in diameter and vary in depth from a shallow one centimetre to a more deliberate seven centimetres, suggesting they were not all made at the same time or with the same intent. The largest sits at the centre of the stone, which may or may not be significant. Around and between the confirmed cupmarks, the surface also carries a number of fainter, ambiguous depressions, and whether these represent unfinished work, experimental marks, or simply the ordinary wear of a lakeshore stone is an open question. A second cupmarked stone lies less than a metre to the north, which raises the possibility that this was once a more deliberate arrangement rather than an isolated curiosity. Lough Hyne itself is a marine lough connected to the sea by a narrow tidal rapids, and its shores have long attracted human activity, though the precise period in which these carvings were made has not been established.