These sites, known in Irish as cillíní (singular cillín), were set apart from consecrated ground and used for the burial of unbaptised infants, and occasionally others considered ineligible for a churchyard grave. Quiet, often unmarked, and frequently located at the edges of fields or beside ancient enclosures, they occupied a threshold space, neither fully inside nor outside the community's sacred geography.

The practice of burying unbaptised children in separate ground was rooted in theological doctrine that held baptism as a prerequisite for entry to consecrated soil. In Catholic Ireland this endured well into the twentieth century, with families carrying infants to these liminal spots, sometimes under cover of darkness, and marking graves with small stones or nothing at all. The Muckinish site sits within a landscape already layered with early medieval and prehistoric remains, as the Burren's limestone terrain preserves earthworks, field systems, and ecclesiastical ruins in unusual density. The precise history of this particular cillín, including when it was established or last used, is not currently documented in available sources.