These small, unconsecrated plots were used for centuries to inter unbaptised infants, and sometimes others considered outside the bounds of formal Catholic burial, including stillborn children, strangers, and the poor. Set apart from the main parish graveyard, a cillín occupied a liminal space in both the physical and spiritual landscape, neither fully of the community nor entirely separate from it. Their locations were often ancient, reusing pre-Christian enclosures or marginal ground at the edges of fields and bogs, and their existence speaks quietly to the intersection of official religious practice and the older, more local customs that persisted alongside it.

Cillíní are found across Ireland in their hundreds, perhaps thousands, and Mayo has a particularly high concentration of them. The practice of burying unbaptised children in such places was widespread from the medieval period onward and continued in some areas well into the twentieth century. The grief associated with these sites was real and enduring, yet the burials were often carried out without ceremony, sometimes at night, by a small number of family members. Unmarked stones, if anything at all, indicated the graves. Over time many cillíní became overgrown or forgotten, their significance surviving mainly in local memory and in the names attached to fields and corners of the landscape. The one at Cunnagher is recorded as a monument, placing it within a broader effort to document and protect these sites across the country.