This is a killeen, a type of unconsecrated burial ground used in Ireland for centuries to inter unbaptised infants and others considered ineligible for burial in consecrated ground. The Church's position on original sin meant that children who died before baptism occupied an ambiguous status in death, and killeens, often early medieval enclosures repurposed for the purpose, became the places communities set aside for them. The Cloon example is unusually well-furnished for such a site, with several significant early medieval stone features still present within the enclosure.

The enclosed area measures approximately 35 metres north to south and 37 metres east to west, defined by a low, overgrown bank that stands around half a metre high on its inner face. A well-defined entrance gap, just over a metre wide, opens at the north-north-east, and from there the internal stone-facing of the bank is virtually continuous around to the south-south-west, where it begins to deteriorate. The western arc survives only as vague traces. Inside the enclosure, concentrated in the south-eastern quadrant, are three particularly notable features: a leacht, a bullaun stone, and a cross-inscribed pillar stone. A leacht is a low, roughly built cairn or platform associated with early Christian devotional practice, sometimes marking a grave or commemorating a saint. Bullaun stones are boulders or slabs bearing one or more rounded depressions, likely used for grinding or in ritual contexts, and are commonly found at early ecclesiastical sites across Ireland. That this killeen contains such objects suggests it was adapted from, or developed alongside, a much older sacred enclosure rather than being established from scratch as a peripheral burial place.