A rath is a ringfort, one of the thousands of circular earthwork enclosures, typically dating from the early medieval period, that are scattered across the Irish countryside. Most were built as farmsteads or places of habitation. This one acquired a different purpose in the centuries that followed: it became a killouragh, or cillin, an informal burial ground reserved for unbaptised infants, who were excluded from consecrated ground under Catholic practice and so were laid to rest in marginal places, at field boundaries, on shorelines, and within the banks of ancient earthworks.

The Kerry Field Club recorded in 1946, drawing on local memory of the preceding years, that the rath at Boolacullane had been used until relatively recently as a killouragh for the burial of unbaptised children. The dual layering of time here is notable: an early medieval enclosure repurposed, over how many generations is unclear, as a place of clandestine mourning. Inside the rath, a number of small humps in the ground may indicate individual graves, though no markers of any kind are visible. The absence of headstones or inscriptions was typical of killouraighs, where burial was carried out without ceremony and without the formal commemoration that consecrated interment would have permitted.