One is a chevron-like design, angular and deliberate, cut into the stone surface and oriented inward toward the cairn's interior. Just above it, on the same face, is a smaller mark that resembles an arrow turned on its side. Neither is dramatic. Both are the kind of thing that rewards patience and low light.

The cairn itself, a mound of stones built up over a burial or ceremonial space in prehistoric times, sits on a hilltop at Derreenacarrin in County Cork. Rock art of this kind, geometric motifs inscribed on exposed stone surfaces, is generally associated with the Neolithic and early Bronze Age periods in Ireland, though precise dating of individual sites remains difficult. What makes this example quietly interesting is its placement: the decorated slab faces inward rather than outward, suggesting the marks were meant to be seen from within, or perhaps never meant for ordinary viewing at all. Whether they served a ritual function, marked ownership or identity, or carried some meaning now entirely lost is unknown. The geometry itself, chevrons and directional forms, does appear at other Irish rock art sites, though each example tends to carry its own local character.