That ambiguity is, in a way, the whole story. Cup marks, the simplest and most widespread form of prehistoric rock art found in Ireland, are shallow circular depressions ground or pecked into stone surfaces, their precise meaning and age still debated by archaeologists. The example recorded at Ballykean was never elaborate: just nine shallow cups on a single flat stone, sitting on level ground among the natural outcrops.

The stone was documented in 1884 by G.H. Kinahan, who catalogued it as Stone C and noted its nine cups in a published account. When investigators returned to the site in 1990, they could not find it. The stone had not been recorded as removed or destroyed, it simply was not there. Whether it had been buried by encroaching vegetation and soil, incorporated into a field boundary, or had always been easy to overlook, the record offers no answer. What remains is a nineteenth-century description pointing to a location, and a twentieth-century search that came up empty.