Rather than being remembered as a fortification or a farmstead boundary, it is traditionally understood by people in the area to be a children's burial ground, placing it within a category of site that was once far more common across Ireland than formal records tend to acknowledge.

These burial grounds for children, often called cillíní or killeens, were places where infants who died before baptism were interred outside the bounds of consecrated ground. Catholic doctrine, as it was historically understood in rural Ireland, held that unbaptised children could not be buried in a churchyard, and so communities quietly set aside other spaces, frequently ancient or liminal ones, ring forts, old enclosures, shorelines, and boundaries, for these small graves. The cashel at Colesgrove fits that pattern precisely. Its reuse as a burial place for the unbaptised draws on a long tradition of layering new meaning onto older structures, the pre-Christian past pressed into service for a distinctly post-Reformation pastoral need. The association at Colesgrove is preserved through local memory rather than written documentation, which is itself characteristic of cillíní; they were rarely recorded officially and their histories travelled by word of mouth across generations.