It is, in fact, the base of a cross, and what makes it quietly arresting is precisely what it lacks: the cross itself is gone, leaving only the socket where the shaft once fitted, a rectangular void measuring roughly twelve centimetres by eight, cut just two centimetres deep into the stone. The block is trapezoidal, wider at the base than at the top, and stands only twenty-six centimetres high. It is the kind of fragment that speaks more to loss than to survival.

The stone was first recorded by the scholar R. A. S. Macalister in 1916 to 1917, when he found it at the north wall of the nave of St. Caimin's church on the island. Inis Cealtra, also known as Holy Island, was an important early Christian monastic site, and St. Caimin's church is one of several ecclesiastical remains clustered there. By the time the stone came to be documented formally, it had already been separated from whatever cross it once anchored. It is now kept in the OPW chalet on the island, removed from its original position and sheltered from further weathering.

Visitors to Inis Cealtra reach the island by boat from Mountshannon on the Clare shore, and the monastic remains are the main draw. The chalet where this cross base is now housed sits among those ruins, and the fragment is easy to overlook among more complete and more visually commanding stones nearby. Its interest lies in the socket, that small deliberate cut into sandstone that was made to hold something upright and permanent, and which has now outlasted whatever it was designed to support.