The surface is lichen-encrusted and uneven, and the rock art carved into it is, by any honest assessment, not readily visible. Yet look carefully, and individual pickmarks begin to resolve themselves out of the texture of the stone, along with faint strands of picking that suggest a deliberate, if lightly applied, hand.

The boulder measures roughly three metres on its east-to-south axis and about one metre north-to-south, rising to approximately a metre in height. Identified and described by Aoibheann Lambe in March 2023, its upper surface carries two motifs of the cup-and-ring type, a form of prehistoric carving found across Atlantic Europe and Ireland, in which a small circular depression, the cup, is surrounded by one or more incised rings. Here, the more distinct of the two shows a cup four centimetres in diameter enclosed within two concentric rings, the outer reaching twenty centimetres across. The second motif is fainter, a cup of the same size within a single ring of ten centimetres, and the two are separated by a natural crack running through the rock face. Cup-and-ring art is generally attributed to the later Neolithic or early Bronze Age, though its precise meaning or function remains genuinely unresolved. The lightly worked quality of the rings at Derreeny suggests either a different tool, a different technique, or simply the passage of a very great deal of time.

The boulder is described as inconspicuous in its landscape, which is worth taking seriously as a practical observation. It sits in open upland terrain that offers clear views towards the Ballaghbeama gap and down into the Kealduff River Valley, a setting that may or may not have mattered to whoever made these marks. What is certain is that finding the panel requires patience, and reading it requires conditions that favour low, raking light to pick out the shallow incisions against the surrounding roughness of the stone.