Locally known as 'the Cilleens', a term derived from the Irish word for a small church or a children's burial ground, it contains an overgrown enclosure that went entirely unrecorded on the Ordnance Survey maps of 1842 and 1905, only appearing on the 1936 edition as a modest rectangular outline defined by a dotted line. That cartographic silence across nearly a century is itself telling, the kind of gap that often surrounds places considered marginal, unofficial, or simply too painful for formal acknowledgement.

Cilleens, sometimes spelled cilliní, were used across Ireland for the burial of unbaptised infants, and occasionally suicides or others excluded from consecrated ground by Church law. They occupy an ambiguous space in the landscape, neither parish graveyard nor wilderness, tended by memory more than by institution. The site at Killagrohan sits on a south-west-facing slope in pasture, and what survives on the ground is a subcircular area roughly 25 metres north to south and 26 metres east to west. An earthen bank runs along the north-east to west-south-west arc, with what appears to be a collapsed or scarped bank continuing north-westward. The interior is raised and saucer-shaped, littered with loose stones, and some grave markers have been noted among the vegetation. The field name was recorded by Power in 1932, suggesting that local knowledge of the site's function persisted even when the maps ignored it entirely.