These sites, known in Irish as cilliní (singular cillín), were used for centuries to inter unbaptised infants and others considered ineligible for burial in consecrated ground under Catholic canon law. The logic was stark: without the sacrament of baptism, a child was held to exist in a kind of ecclesiastical limbo, and so the earth that received them had to be marginal too, neither fully sacred nor wholly profane. Boundaries were the preferred locations, whether the edges of fields, old ringforts, or shorelines, places already outside the ordinary rhythm of the living world.

Cilliní are found across Ireland in their hundreds, perhaps thousands, and Mayo has a significant concentration of them. They tend to be modest in appearance, sometimes marked by small uninscribed stones, sometimes with no visible marker at all, which is part of what makes them so easy to overlook. The grief attached to them was often private, even silent, carried by families who had little recourse within the formal structures of the church. In recent decades, archaeological and historical attention to cilliní has grown considerably, with researchers recognising them as a distinct and meaningful category of burial site rather than simply an absence of proper interment. The townland name Na Sraithíní itself suggests a landscape of ridges or strips, the kind of terrain common in the west of Ireland where land was worked in narrow cultivated bands.