These quiet, often unmarked plots were used for centuries to inter unbaptised infants and others considered ineligible for burial in consecrated ground under Catholic Church law. They tend to occupy liminal spaces in the landscape, old ringfort interiors, field boundaries, coastal dunes, or the edges of ancient ecclesiastical enclosures, and Killarriv's example belongs to this widespread but frequently overlooked tradition of alternative burial practice.

Cilliní were in use across Ireland roughly from the medieval period through to the mid-twentieth century, though the practice varied by region and community. Because unbaptised children were excluded from formal church burial, families interred them in these separate, informal grounds, which were nonetheless treated with care and, in many cases, quiet reverence. The sites were rarely documented in official records and their locations were passed down through local memory rather than written sources. Killarriv, in the west of Ireland, sits within a region where this tradition persisted well into living memory for older generations, and where the landscape still holds numerous such sites, many of them unexcavated and largely undisturbed.