Known in Irish as a cillín (plural cilliní), these were informal, unconsecrated plots used for centuries to inter unbaptised infants, stillborns, and occasionally others who, for one reason or another, were refused burial in the parish churchyard. They occupy a particular kind of in-between space, neither fully domestic nor formally sacred, often tucked along field margins, beside old boundary walls, or at the edges of ancient ecclesiastical sites.

The use of cilliní in Ireland spans a long period, from at least the early medieval era through to the twentieth century in some rural areas. Church teaching historically denied Christian burial to the unbaptised, and so communities developed their own quiet solutions, choosing liminal spots in the landscape where the ground had some sense of age or sanctity without the gatekeeping of the parish. The sites were rarely marked with inscribed headstones, and their locations were passed on through local memory rather than official record. As a result, many have become difficult to trace, overgrown or absorbed into farmland, their existence sustained only by townland knowledge and the occasional small stone or slight rise in the ground.