These were the resting places for unbaptised children, and sometimes others considered outside the formal rites of the Catholic Church, who could not be interred in consecrated ground. The one at Keenagh Beg, in County Mayo, is one of hundreds of such sites recorded across the island, each carrying the quiet weight of a practice that endured for centuries and ended, in most places, only within living memory.

The theological reasoning behind cillíní was straightforward if bleak: a child who died before baptism was held, under Catholic doctrine, to be excluded from heaven, and by extension from the churchyard shared by the baptised community. Families had little choice but to find other ground. The sites chosen were often liminal in character, places already set apart from everyday use: old ringfort banks, shorelines, field boundaries, or land associated with earlier, pre-Christian burial. Cillín sites in Connacht are particularly dense, reflecting both the region's demographics and the survival of the tradition into the twentieth century. The site at Keenagh Beg sits within this wider pattern, a small townland in Mayo where the ground still holds its particular history.