What was once a gravemarker standing outside the west end of St. Mary's church on Inis Cealtra, the island monastery in Lough Derg on the Clare shoreline, now rests against the north wall of the nave, roughly three metres from the west gable. The shift itself is a small reminder of how early medieval stonework tends to accumulate a secondary life, migrating indoors or into walls long after its original context has dissolved.

The slab was recorded by the antiquarian R.A.S. Macalister in a 1916 to 1917 survey, where he catalogued it as no. 65 and described it as being of twelfth-century type. It measures approximately 55 centimetres by 53 centimetres, and is only about eight centimetres thick, a modest fragment that carries the upper portion of a Latin cross with hollowed angles. Hollowed or scooped angles, sometimes called armpits, are a decorative feature found on Irish cross-slabs from the early Christian period, where the spaces between the arms of the cross are cut away to emphasise the cross shape itself. At the time Macalister saw it, the slab was still outside, doing quiet duty as a grave marker. Whether it marked the original burial or had simply been pressed into later use by then is not known.