These burial grounds, known in Irish as cilліní (singular cillín), were used for centuries to inter unbaptised infants and others considered outside the bounds of consecrated ground, including stillborn children and occasionally those who had died by suicide or were otherwise excluded from Catholic burial rites. They occupy a particular and melancholy position in Irish social history, shaped by theological rules that denied unbaptised souls entry to heaven and, by extension, entry to the parish churchyard.

The practice of using such liminal spaces, often on the margins of townlands, near ancient earthworks, or at the boundaries of fields, persisted well into the twentieth century in parts of rural Ireland. Carn, like many Mayo townlands, would have known generations of quiet, informal burials carried out without clergy, without ceremony, and often without any marker that survives today. The choice of location was rarely random; older ground, already associated with sanctity or antiquity, was often preferred, and the boundaries between the living community and these small, unconsecrated plots were carefully, if informally, maintained.

Beyond the fact of its existence at Carn, the specific history of this particular site remains undocumented in any publicly available form at present, which is itself a kind of answer. Many cilліní across Ireland are in precisely this condition: known locally, mapped in passing, but not yet fully recorded. The ground is there; the knowledge of what happened there is still partly held by the landscape itself.