Known in Irish as a cillín (plural: cilліní), these informal burial grounds were used for centuries across Ireland to inter infants who had died before receiving the sacrament of baptism. Catholic doctrine, as it was widely understood and practised, held that such children could not be buried in consecrated ground, and so communities found other places, often ancient, liminal spots such as old ringfort banks, cliff edges, or unconsecrated field corners, where the small dead could be laid to rest with a degree of care, if not official sanction.

The practice was widespread from at least the medieval period through to the mid-twentieth century, and cilліní are found in their hundreds across Ireland, Clare included. They were rarely marked with formal headstones, and many survive only as faint earthwork irregularities or as sites known through local oral tradition rather than any official record. The grief surrounding them was often private and unacknowledged, and the sites themselves occupy an ambiguous place in Irish social and religious history, belonging neither fully to the Church nor entirely outside it. Castlecrine, a rural townland in the east of the county, sits in a landscape with deep layers of early settlement, and the presence of such a burial ground here fits a broader pattern across Clare and the wider west of Ireland.