Near its north-western edge stands an elongated boulder carrying a simple inscribed cross. Nothing about it announces itself loudly, yet local tradition insists this quiet, stony rise is a graveyard, and more specifically a place where unbaptised children were laid to rest.

The burial of unbaptised infants outside consecrated ground was a widespread practice in Ireland, rooted in Catholic doctrine that held such children, having died before baptism, could not be admitted to heaven and therefore could not be buried in the parish churchyard. These informal burial places, sometimes called cillíní or killeens, tend to occupy marginal or ancient ground, and they are scattered across the Irish countryside, often marked by little more than field tradition and the faint disturbance of the earth. The inscribed cross-stone at Coole suggests the site had at least some degree of acknowledgement, perhaps as a marker of the liminal space between the fully churched and the quietly forgotten. The simplicity of the cross, a single incised design on a rough boulder rather than a dressed and lettered headstone, is typical of the informal commemorative language of such places.