Look more carefully and the interior resolves into a field of grave-markers, most of them small set stones, the kind of modest, uncarved markers that are easy to overlook and impossible to mistake once you know what they signify. This is a cillín, a burial ground of the kind once found across rural Ireland where unbaptised children, and in some cases stillborn infants, were laid to rest outside the boundaries of consecrated ground. Excluded by Church law from formal Christian burial, they were nonetheless given to the earth with care, in places that carried their own quiet sanctity.

The site sits immediately to the south-east of an ecclesiastical building of some antiquity, a proximity that was probably deliberate rather than incidental. The platform measures roughly 13.5 metres north to south and 7.7 metres east to west, with a wide, shallow fosse, essentially a ditch or depression, visible at the north-east corner. What makes Cloonsheen slightly unusual among cillíní is the evidence of adult burials in the northern section, where graves are defined by more substantial slabs rather than small set stones. The reference work by Gwynn and Hadcock, published in 1970 and dealing with medieval religious houses and sites, notes the location, suggesting the ground here has a long history of use connected to an earlier ecclesiastical presence. Local knowledge recorded during survey work indicates that children continued to be buried here until quite recently, meaning the site remained in active, if informal, use well into living memory rather than fading out in some distant past.