These sites, known in Irish as cilliní (singular: cillín), were used for centuries as informal burial places for unbaptised infants, who, under Catholic doctrine, could not be interred in consecrated ground. The locations chosen were often liminal, occupying the edges of parishes, old ringfort banks, or forgotten field margins, places that existed, in a sense, between the official and the unofficial worlds.

The practice of burying unbaptised children in separate, unconsecrated ground persisted in Ireland from the medieval period well into the twentieth century. Parents who lost infants before baptism, or whose children were stillborn, had few alternatives within the formal Church structure. The cilliní became the quiet solution, tended by families rather than clergy, acknowledged locally but rarely documented in parish records. In Mayo, where rural communities remained closely tied to older customs longer than in more urbanised parts of the country, such sites were maintained with a kind of careful, private dignity. The Troiste site is one of many in the county, each carrying a similar weight of unrecorded grief and community memory.