It measures roughly twenty metres north to south and seventeen metres east to west, and rises only about a third of a metre from the surrounding ground. What elevates it above an unremarkable field feature is the practice once associated with it: this was a place where unbaptised infants were brought to be buried.

The site is reputedly the location of the monastery of Killansnamh, said to have stood directly opposite Narrowwater Castle on the far bank of the Newry River. Around 1837, some visible remains of the abbey were still present, enough that the place retained a clear identity in local memory. The burial of unbaptised infants at former ecclesiastical sites was a widespread custom in Ireland, rooted in the theological anxiety surrounding limbo, the supposed state of souls who died without baptism. Such children could not be interred in consecrated ground according to official Church practice, and so communities often turned to older, liminal sacred spaces, places that existed just outside formal religious jurisdiction yet carried an unmistakeable sense of sanctity. By the time the nineteenth century was well advanced, the stonework at Cornamucklagh had largely disappeared, leaving only the low platform that survives today.

The site sits on the eastern slope of a natural ridge and the orientation towards Narrowwater Castle, visible across the water, gives some sense of the local geography that made Killansnamh a landmark in its time. There is little now to signal the site's former significance other than the slight rise of stones in the ground, but that understatement is perhaps appropriate for a place that served, quietly and outside official record, as the resting ground of the unbaptised dead.