It once held the shaft of a standing cross. The shaft itself, or what may be a fragment of it, lies nearby on a leacht, a low commemorative stone cairn or slab-altar of the kind found at early Irish monastic sites, sometimes used as a focus for prayer or penitential circuits. The fragment and the socket appear to fit one another, though the fragment now shows no decoration, raising the quiet puzzle of whether any carving it once bore has simply worn away, or whether the carved piece recorded in the nineteenth century was something else again.

St Macdara's Island, known in Irish as Cruach na Cara, preserves one of the most complete early medieval church buildings in the west of Ireland, and this cross fragment sits within the ecclesiastical enclosure roughly 20 metres to the north-east of the church. When the antiquarian Kinehan visited in 1869, he recorded a rectangular piece of limestone carved on both sides resting on the leacht and suggested it might be part of a cross shaft, noting that the socket nearby seemed to correspond to it. By the time Francis Joseph Bigger examined the site in 1896, the picture had become less certain; the fragment recorded on the leacht was undecorated. Whether the carved piece Kinehan saw had been moved, lost, or simply misidentified is not clear. What remains is the socket, still visible in the ground to the south-east of a cross-slab that stands close by, and the modest limestone fragment measuring 42 centimetres long and 32 centimetres wide, sitting where it may or may not have always been.