A rath is an Early Medieval enclosed settlement, typically circular, formed by one or more earthen banks and ditches, and once common across Ireland in the thousands. This one, roughly forty metres across, sat on a gentle rise in undulating pastureland and was already reduced enough by 1838 that the Ordnance Survey cartographers noted it as a circular enclosure rather than a standing earthwork. Today there is no visible surface trace at all.

What the 1838 OS six-inch map recorded has since been further erased by a field boundary running roughly north to south, cutting across the interior from the north-west to the south-west. That kind of incremental loss is common with raths: boundaries get redrawn, land gets improved, and the earthworks are gradually levelled or ploughed out over generations. What makes Parkaloughan unusual is what occupies the space now. The interior of the vanished enclosure contains a children's burial ground, a type of site known in Irish tradition as a cillín, where unbaptised infants and others excluded from consecrated ground were quietly interred, often over many centuries. The pairing is not entirely coincidental; raths and other ancient enclosures were frequently chosen as burial sites for children, perhaps because the marginal or liminal character of such places made them feel appropriate for those who occupied an uncertain position in the religious landscape of rural Catholic Ireland.