What makes it worth pausing over is what lies beneath that weathering: a carved surface roughly ninety centimetres square, packed with prehistoric decoration that has no obvious practical explanation and has resisted any definitive one for as long as people have studied it.

The carvings belong to the tradition known as rock art, a broad category of prehistoric mark-making found widely across Atlantic Europe and concentrated in Ireland along the western seaboard. The dominant motifs here are cup-and-ring marks, which are exactly what the name suggests: a shallow, roughly circular depression, or cup, surrounded by one or more incised rings. On this boulder, two such motifs sit at the north-western side of the decorated face, connected by a network of curving grooves that researchers have described as forming something close to a honeycomb pattern. A curvilinear groove extends further across the stone surface from that central network, and a pair of cupmarks to the south-west are joined by a short groove and enclosed within an open oval of pickmarks. A semi-circle of pickmarks sits near the edge of the stone to the north. The whole composition is confined to a single quadrant of the rock face, defined on one side by a natural fracture in the sandstone, as though whoever made it was working deliberately within a boundary already given to them by the stone. The site sits at 172 metres above sea level, facing north-east, with long views down towards Lough Brin; the steep mountain landscape rises sharply to the west.

At some point the boulder was incorporated into a small field boundary, which is both what helped preserve it in place and what makes it easy to overlook. The lichen and weathering are significant; the carving is not crisp, and reading the full pattern requires patience and good light. The site was recorded in detail in the archaeological survey of the Iveragh Peninsula by A. O'Sullivan and J. Sheehan, published by Cork University Press in 1996, drawing also on earlier fieldwork by Finlay in 1973.