The stone slab, measuring over 72 centimetres tall and roughly 36.5 centimetres at its widest point, has a distinctive shape; its rounded head bulges noticeably on the right side before narrowing dramatically to form a slender base. Set slightly off-centre on the broad south-eastern face, a Latin cross has been carved into the stone using deep, broad grooves that create a striking relief against the weathered surface.

The cross itself spans 42 centimetres in height and 28.5 centimetres across its arms, with careful attention paid to its design details. Where the shaft and transom meet, the grooves widen subtly to form a lozenge-shaped expansion at the centre, whilst the terminals of the head and arms feature simple rounded endings. The foot of the cross shows particular craftsmanship, with a triangular expansion and converging lines that create the appearance of a small pedestal. In more recent times, lighthouse keepers applied red paint to highlight the carving, making the ancient symbol stand out dramatically against the grey stone.

The slab has been carefully positioned at the western end of the oratory, oriented 240 degrees west, or about 30 degrees south of west, and stands upright against a stone structure built along the building’s north wall. First documented comprehensively by Herity in 1995 and photographed by Paul Walsh in July 1983, this cross-slab represents the enduring tradition of stone carving that marked sacred spaces throughout medieval Ireland, its simple yet deliberate design speaking to both the skill of its creators and the spiritual significance of the site.