These are cup marks, among the simplest and most enigmatic forms of prehistoric rock art found across Ireland and Britain: deliberately pecked circular hollows, ground into stone surfaces during the Bronze Age or possibly earlier, their precise meaning long since lost. What remains is the physical fact of them, worn and weathered into the granite over thousands of years.

The boulder itself is earthfast, meaning it is set firmly into the ground rather than a portable object, and it is substantial: roughly 3.2 metres north to south and 3 metres east to west, rising to about 0.7 metres at its northern edge. The cup marks are concentrated at the highest point of the stone. The two most prominent measure 6 centimetres and 8 centimetres across, and are cut to depths of 1 centimetre and 1.5 centimetres respectively. The remaining sixteen are considerably shallower, most averaging only half a centimetre deep and ranging between 3.5 and 4.5 centimetres in diameter. That shallowness, combined with general weathering, makes several of them difficult to read clearly against the surrounding granite surface.

The setting adds a quiet layer of interest. The slope faces north, and on a clear day the panorama takes in Raven Rock and Two Rock Mountain to the north-west, the narrow gap of the Scalp defile to the north-north-west, Carrickgollogan to the north, and Killiney Hill to the north-east. Whether that orientation or those distant landmarks held any significance for the people who made the marks is unknown, but the placement of the stone within a tree ring suggests the site accumulated meaning across more than one period of use.