The stone is earthfast, meaning it is fixed in the ground rather than placed on it, and its decorated surface measures just over a metre across. The motifs carved into it are prehistoric rock art, specifically the cup-and-ring type: shallow circular grooves cut concentrically around a central cupmark, a form found across Atlantic Europe and Ireland from the Neolithic and Bronze Age periods, though their purpose remains genuinely unknown. What makes this particular boulder awkward to find, and in some ways more interesting for it, is that the valley side is strewn with rock outcrops and loose scree, and the markings themselves are extremely faint, partially obscured by white and grey lichens on the upper surface and black mosses creeping across the lower portion.

The decorated surface holds several distinct motifs. Two cup-and-four-ring designs, each roughly twenty centimetres across, are the most legible; one of these has a radial groove extending from the central cup outward through the rings, a feature sometimes interpreted as a channel or avenue in the design. There are also faint traces of a cup-and-three-ring motif, four curvilinear grooves, and a single isolated cupmark. The rings themselves are carved to a depth of only one or two millimetres, which partly accounts for why they are so difficult to read in flat light. J. Cuppage documented the stone in the 1986 Dingle Peninsula archaeological survey of Corca Dhuibhne, and a note by Finlay from 1973 records that two further decorated rock surfaces were known in the immediate vicinity of the lake, though their precise locations were never recorded. Rock art also appears further down the valley, associated with an extensive pre-bog field system, suggesting this area was a meaningful and repeatedly used landscape in prehistory rather than an isolated curiosity.