The decorated surface measures only forty centimetres by thirty, a modest patch on a rock that stands over a metre high and stretches nearly four metres across. Within that patch, two motifs survive: an oval cupmark, roughly eight centimetres at its widest and eight millimetres deep, sitting slightly off-centre to the west; and a linear groove running east to west for twenty-six centimetres, with a short return of thirteen centimetres at its western end, positioned just a few centimetres to the northeast of the cupmark. Cupmarks are among the most widespread and least understood forms of prehistoric rock art, shallow depressions pecked or ground into stone surfaces, found across Ireland and much of Atlantic Europe. What they signified, and to whom, remains genuinely open.

The boulder sits at around 167 metres above sea level on a northwest-facing slope at Ballynakilly, with mountains rising to the northeast, east, and south, and the Behy River valley opening out to the north. The rock itself is slightly rough and fractured sandstone, the decorated face oriented towards the southeast. A thicket of furze bushes grows close to the east side. The setting is one of scattered outcrops and boulders in rough pasture, the kind of upland landscape that contains far more archaeology than its present quietness might suggest. The decorated surface, modest in scale, faces away from the mountains and out towards the lower ground, a detail that may or may not carry meaning but is worth noting when standing there.