First identified by researcher M.A.M. Van Hoek in 1987, this stone features what he described as a probable cupmark; a small, deliberately carved hollow on its southern edge. The boulder, which may actually be part of a larger outcrop, rests in a sheltered position where sand and grass meet the hillside.

Cupmarks are amongst the simplest yet most enigmatic forms of prehistoric art found across Ireland and Britain. These circular depressions, typically carved into stone surfaces during the Neolithic and Bronze Age periods, appear both as solitary marks and in complex arrangements with other rock art motifs. While their exact purpose remains a mystery, theories range from territorial markers to astronomical alignments, ritual significance, or even primitive mapping systems. The isolated nature of this particular example at Carrickabraghy makes interpretation particularly challenging.

Van Hoek’s survey work in County Donegal during the 1980s brought attention to numerous previously unrecorded examples of rock art in the region, contributing significantly to our understanding of prehistoric activity in northwest Ireland. His cautious description of this marking as “probable” reflects the scholarly approach needed when documenting weathered stone surfaces that have endured thousands of years of Irish weather. The sheltered position of this boulder may have helped preserve whatever ancient markings it bears, though time and the elements have clearly taken their toll on the clarity of the carving.