Whether it is still there is, genuinely, unknown.

Inishshark, one of the more remote of the Galway islands, contains the remains of St. Leo's Chapel, a site associated with early Christian activity in the region. Cross-slabs, which are flat stones bearing an incised or relief cross, are among the most widespread early medieval monuments in Ireland, often marking graves or serving as focal points for devotion at ecclesiastical sites. In 1913, the antiquarian H.S. Crawford catalogued this particular example as part of a descriptive survey of early cross-slabs and pillars published in the Journal of the Royal Society of Antiquaries of Ireland, noting simply a broken slab with a cross incised on it. When J.G. Higgins revisited the evidence for his 1987 study of County Galway's early Christian stone monuments, a site visit carried out in August 1984 failed to locate it. The slab had either been moved, buried beneath accumulated debris, or lost entirely in the decades since Crawford's record.

The island's evacuation in 1960, when its last remaining residents were resettled on the mainland, left its structures unattended and subject to slow collapse and overgrowth. It is the kind of place where things disappear not through drama but through neglect and weather and time. The cross-slab, if it survives at all, presumably remains somewhere within or near the chapel, unidentified.