Known in Irish as a cillín (the plural being cilliní), these were informal burial sites used for unbaptised infants and, in some cases, others considered to occupy an ambiguous spiritual status, people who for various reasons could not be interred in consecrated ground. The Catholic Church's historical teaching that unbaptised children could not enter heaven meant that grieving families were left to find their own ground, often on the margins of parishes, near old ringforts, on clifftops, or tucked against boundary ditches. The result is a particular kind of site, neither fully sacred nor fully secular, that can be extraordinarily difficult to read in the landscape.

Cilliní are found in their hundreds across Ireland, and Mayo has a significant concentration of them, reflecting both the density of rural settlement in the west and the long persistence of traditional practice in the region. The locations chosen were rarely random. Liminal places carried weight, and families returned to the same spots across generations, sometimes over centuries, leaving little more than small unmarked stones or slight ground disturbances that are easy to miss entirely. Askillaun sits in a part of Mayo shaped by Atlantic exposure, scattered settlement, and a history of land pressure and poverty that made the informal geography of burial all the more necessary. Without more specific documentation available for this particular site, the precise history of its use remains to be fully recorded, but its existence fits a pattern deeply woven into the fabric of post-medieval Irish rural life.

For anyone who comes across a cillín in the landscape, the appropriate response is one of care. These are not derelict or abandoned places in any simple sense; many are still known and respected by local families, and some communities have undertaken quiet acts of maintenance and commemoration in recent decades, reflecting a shift in how Irish society thinks about the children once buried without ceremony in unconsecrated ground.