It is not large by any dramatic measure, running just over a metre in length and less than a metre wide, but its surface carries marks that were made long before anyone thought to build a field boundary nearby. Five cup marks, the simple circular depressions that represent one of the most widespread and least understood forms of prehistoric carving in Ireland, are worked into the stone. Two are substantial, between nine and eleven centimetres across and cut to a depth of two and a half centimetres; the remaining three are smaller and shallower, ranging from five to seven centimetres in diameter and no more than a centimetre deep.

Cup marks are among the oldest human-made markings found in the Irish landscape, generally associated with the Neolithic and Bronze Age periods, though their precise purpose remains genuinely unclear. They appear on boulders, outcrops, and passage tomb kerbs across the island, sometimes in elaborate compositions, sometimes, as here, in modest clusters with no obvious pattern. The Wicklow uplands and their margins contain a number of such marked stones, the granite geology of the region lending itself to this kind of carving. What is striking about the Drummin example is its setting: a reclaimed slope, an old field bank, a boulder that has clearly been incorporated into a working agricultural landscape at some point and yet has kept its prehistoric marks through all of that use and change.