What was once a defined sacred enclosure is now buried beneath large boulders, placed there during land reclamation works sometime before an inspection carried out in 1996. The ground is still there, technically, but it is no longer legible as a place.

Sites of this kind, known in Irish as cillíní (the singular is cillín), were used for centuries to inter unbaptised infants and others considered ineligible for consecrated ground. They tend to occupy liminal spots, at parish boundaries, beside water, or on the edges of townlands, and this one is no exception, pressed up against the lakeshore to its south. It appears on the Ordnance Survey six-inch map of 1838 under the name Killeencormac Grave Yard, and again on the 1922 edition, this time labelled Rinnakilleen. The 1838 Ordnance Survey Letters, a remarkable series of field notes compiled during the mapping of Ireland, recorded it as both a burying place for children and the site of a church, suggesting the location had ecclesiastical significance before it became associated primarily with infant burial. Local memory, gathered at some point before the 1996 inspection, describes the original enclosure as a circular area marked out by a series of low upright stones, a form quite different from the subrectangular outline of roughly fifty metres by thirty that the maps suggest, which may reflect centuries of gradual change or simply the difference between what was once visible above ground and what the cartographers chose to record.