The carvings are cup-and-ring marks, a form of prehistoric rock art found across Atlantic Europe and Ireland, consisting of a central cupmark, a shallow circular depression pecked into the stone, surrounded by one or more incised rings. At Derrynablaha, the decorated surface is modest, roughly 0.65 metres wide, and the two motifs are concentrated on the western half of the rock, to the west of a natural fracture running north to south. Each has a cupmark of about five centimetres across. The western one is enclosed by a complete ring; the eastern one by a ring that covers only half the cupmark, either left unfinished or worn away on one side.

The site was documented as early as 1963 by Emmanuel Anati and again in 1973 by Finlay, and later incorporated into A. O'Sullivan and J. Sheehan's comprehensive archaeological survey of south Kerry, published by Cork University Press in 1996. The outcrop itself sits at around 104 metres above sea level on a slight north-east-facing slope, close to a stream about ten metres to the north. It is rough and fractured sandstone, not the kind of surface that invites carving without intention. The decorated face has a south-west-facing aspect, which may or may not be coincidental; many Irish rock art sites show a preference for surfaces that catch particular light, though what that meant to the people who made them remains genuinely unclear. A second rock art site lies immediately to the south.

The carvings are described as very weathered but traceable, which is worth bearing in mind for anyone who makes their way out to the heath. Low, raking light, particularly in the morning or late afternoon, tends to pick out shallow surface carving far more clearly than flat midday sun. The farm roadway running about eight metres to the east suggests the site is at least approachable, though upland heath in Kerry is rarely straightforward underfoot.