A rath is a ringfort, typically an Iron Age or early medieval enclosure defined by one or more circular earthen banks, and this one had stood unremarked for centuries before road construction works in 2002 and 2003 required a partial excavation of its interior. What came to light was not the expected traces of early medieval habitation, but something far more recent and more melancholy.

The burial area was small, measuring roughly two metres north to south and four and a half metres east to west, tucked into the northern sector of the rath interior. Between 34 and as many as 60 individuals had been interred there, nearly all of them infants aged between 29 weeks in utero and six months old, with a single adolescent or adult also present. Several graves were marked at head and foot with crude stones. Most of the bones were disturbed and co-mingled, but five oval grave-cuts, oriented roughly east to west in the Christian tradition, contained intact skeletons. Shroud pins recovered from the site, along with iron nails and fragments of pine wood that likely came from small coffins, pointed to the late nineteenth century, a date confirmed by radiocarbon determinations. Sites like this, where unbaptised infants were buried outside consecrated ground, are known in Ireland as cillíní, and they appear in fields, on townland boundaries, in the corners of old raths and ringforts across the country. Catholic doctrine of the period held that unbaptised children could not be buried in consecrated ground, and so families found quieter, older places. Following full excavation and post-excavation analysis, the remains from Carrowkeel were reinterred in Crossmolina graveyard, given at last the formal burial they had been denied.