The pillar stands to the south-west of Teampull Phádraig, one of two early Christian churches on Inchagoill, and it is easy to walk past without fully registering what it is. Less than a metre high, four-sided, tapering as it rises from a wider base, it is made from hard greyish Silurian stone and looks austere at first glance. Look more closely and seven small equal-armed crosses emerge, their ends bifurcated, meaning each arm splits into a shallow fork, carved deeply into three of its four faces: two crosses on each face except the north, which carries one. On the south face, running perpendicularly down towards the ground rather than across it, a two-line inscription is cut with considerable clarity.

The inscription reads, in twenty-three Old Latin characters: LIE LUGUAEDON MACCI MENUEH. The language is Old Latin, the script Roman, and the formula broadly translates as a memorial statement naming Luguaedon, son of Menueh. Scholars have dated it to as early as the sixth century, placing it in the same general period as the earliest ogham stones, those upright memorials inscribed in an alphabet of notched lines that appear widely across early medieval Ireland and Britain. What makes this pillar distinctive is its use of the Roman alphabet rather than ogham, at a time when that choice was far from commonplace in Ireland. The scholar Rynne, citing the inscription in 1995, regarded it as probably the oldest extant Irish inscription in Latin characters, a claim that, if it holds, makes this modest stone one of the more consequential objects in the country.

Inchagoill is accessible only by boat, with ferry services running from Oughterard and Cong during the warmer months. The island has no permanent residents and the two churches, Teampull Phádraig and the Romanesque Teampull na Naomh, sit quietly in woodland. The pillar itself stands just outside Teampull Phádraig, and the inscription on the south face rewards patient looking, particularly in low raking light that sharpens the depth of the carving.