A stoup is a basin for holy water, typically set into a wall or mounted near a church entrance, and this one is unusual in its geometry alone: heptagonal in plan, rectangular in elevation, with a shallow central depression measuring roughly three inches across and four inches deep. The rim is worn in the way that only centuries of use can produce. It is a modest object, easy to overlook, but its presence in this particular porch is the result of a quiet act of removal that took place more than a hundred years ago.

The stoup originally came from Innisfallen Island, a small island in Lough Learne with a monastic history stretching back to the early medieval period. In the 1890s, when some kind of work was being carried out on the island, family members removed the stoup and brought it to Killarney. It passed into the keeping of a local woman, and in 1937 she gave it to Captain D. B. O'Connell, who noted its dimensions carefully and corresponded with Harold Leask of the Office of Public Works about its origins and significance. O'Connell recorded it as eight inches in height and seven inches in width. It is a small thing to have travelled so far and waited so long to be accounted for.