Known in Irish as a cillín (plural: cilliní), these were informal burial places used for unbaptised infants, and sometimes for others considered ineligible for consecrated ground, including stillborn children, those who died by suicide, and occasionally strangers. The Catholic Church's doctrine of limbo, which held that unbaptised souls could not enter heaven, meant that for centuries grieving families had nowhere official to turn. Cilliní were the practical, sorrowful answer: patches of older or unconsecrated ground, often on the edges of ancient ringforts, beside early medieval ecclesiastical enclosures, or at boundaries between townlands, where the bereaved could bury their children without ceremony but also without entirely abandoning them to unmarked wilderness.

Ballycarroll itself is a townland in County Clare, a county whose landscape is threaded with archaeological remains spanning prehistoric, early Christian, and medieval periods. The precise history of this particular cillín, including when it was first used, how long it remained in use, and what physical features it retains today, is not currently documented in any publicly available form. What can be said with confidence is that sites of this type were in active use well into the twentieth century in parts of rural Ireland, and that many have only recently begun to receive formal recognition as places of genuine historical and human significance rather than simply as anomalies on the edge of the official record.