They are easy to miss, which is perhaps part of what makes them worth knowing about. These hollows, known as cup marks, are among the most widespread yet least understood forms of prehistoric rock art found across Ireland and Britain. Deliberately pecked into stone surfaces, they appear on boulders, outcrops, and, as here, on the structural stones of megalithic monuments, though what purpose they served remains genuinely unclear.

The tomb itself is a court tomb, a monument type characteristic of the Irish Neolithic, typically dating to before 3000 BC. Court tombs are named for the open, often semicircular forecourt that fronts the burial galleries, and they are found primarily in the northern half of Ireland. That cup marks appear on one of the roof stones at Drumgollagh places the carving in a tradition of decorating or marking the fabric of megalithic architecture, though whether the marks pre-date, are contemporary with, or post-date the tomb's construction is not recorded. Three marks on a single stone is a modest grouping, but the location on the outer western edge of a chamber roof stone suggests they were positioned to be at least partially visible rather than hidden within the structure.