On its west-facing surface, someone carved a series of marks into the stone, probably thousands of years ago, and then the mountain largely forgot about them. They are still there, worn nearly to invisibility, half-obscured by lichen.

The decorated surface measures about 1.66 metres by 0.89 metres and carries five cup-and-ring motifs along with two plain cupmarks. Cup-and-ring art, one of the most widespread yet least understood art forms of prehistoric Europe, consists of a small circular hollow, the cup, surrounded by one or more incised concentric rings, sometimes connected to the cup or to the outer ring by a carved groove called a radial groove. The Teeromoyle examples follow this grammar closely but with variations: one motif has a radial groove running from the cup outward to the ring; two others have grooves extending from the rings themselves; and two have gapped or partial rings, where the carved circle is incomplete or survives only as a faint arc on one side. The motifs range considerably in size, from an overall diameter of around ten centimetres up to about thirty-one centimetres, and the carving depth throughout is shallow, just two to seven millimetres into the rock surface. Weathering and fracture have taken a further toll; one motif is split by a natural crack running through the cupmark, and at least one ring is so faint it is only legible on its north-eastern side. The boulder sits close to the remains of an old field system on the valley floor between Teeromoyle and Coomacarrea mountains, which raises the quiet question of whether the people who worked that land and those who carved the stone were separated by centuries or by none at all. The site was documented and measured in detail by A. O'Sullivan and J. Sheehan in their 1996 archaeological survey of the Iveragh Peninsula, the broader landmass that includes the Ring of Kerry.