These sites, known in Irish as cillíní (the singular is cillín), were used for centuries to inter unbaptised infants, and occasionally others who were denied burial in consecrated ground under Catholic canon law. They occupy a particular and often melancholy place in rural Irish life, frequently sited at townland boundaries, on marginal land, or beside ancient earthworks, as if located deliberately at the edges of things.

The practice of burying unbaptised children in unconsecrated ground was widespread across Ireland from the medieval period well into the twentieth century. Because infants who died before baptism were considered, under prevailing theological doctrine, to be excluded from heaven, they could not be interred in parish graveyards. Families instead carried them, often at night and without ceremony, to these informal plots. The locations chosen were sometimes pre-Christian in character, places already freighted with a sense of the liminal or sacred, which lent the sites a layered significance that sits uneasily with the grief that created them. Lismulbreeda itself, as a townland name, suggests an older Gaelic place-name tradition, though the specific history of this particular ground remains largely undocumented at present.