The stone is large, roughly quadrangular, and mostly flat on top, though its surface is crossed by natural fissures and pitting. Set into that surface, just southwest of centre, is a smooth, sub-circular depression measuring roughly 28 by 25 centimetres and about six centimetres deep. Scattered elsewhere across the upper face are several smaller cup marks, shallow circular hollows worked into the rock by human hands at some point in prehistory.

Cup marks and cup-and-ring marks are among the oldest forms of deliberate human mark-making found in Ireland and Britain, generally associated with the Neolithic and Bronze Age periods, though precise dating remains difficult because the carvings themselves leave no datable material behind. The larger depression here is notably smooth, suggesting deliberate and possibly repeated working of the stone rather than a casual or incidental mark. The boulder is earth-fast, meaning it is set firmly in the ground rather than a portable object, which may indicate it was always intended as a fixed point in the landscape rather than a functional tool. What that fixed point signified, whether it marked territory, served a ritual purpose, or recorded something else entirely, is not known.