Known in Irish as cillíní, these were unconsecrated plots used for the burial of unbaptised infants, and in some cases suicides, strangers, or others deemed ineligible for interment in consecrated ground under Catholic Church law. The one recorded at An Caiseal in County Mayo is one of many such sites throughout Connacht, a reminder of the grief that once had to be managed quietly, outside the formal boundaries of the parish graveyard.

The practice of burying unbaptised children in separate, liminal spaces, often at boundaries, beside ringforts, or on the margins of older sacred sites, was widespread in Ireland from the medieval period through to the twentieth century. The choice of location was rarely arbitrary. Cillíní were frequently placed at or near ancient monuments, perhaps reflecting a folk understanding that such ground carried its own older sanctity, or simply that it lay outside the jurisdiction of the Church. An Caiseal, the placename itself suggesting a stone fort or enclosure, the Irish word caiseal referring to a circular stone cashel, is the kind of site where these layered uses of landscape become legible, a place where early medieval settlement, later folk practice, and quiet communal memory converge.