By the time the Ordnance Survey revised its six-inch maps around 1900, the site had already disappeared from the record entirely, gone without replacement or explanation.

The 1839 OS six-inch map, the first systematic large-scale survey of Ireland, marked the location simply as "Site of Killeen Grave Yard", a phrasing that suggests even nineteenth-century surveyors were working from memory and inference rather than visible remains. The accompanying OS Letters, a series of detailed descriptive notes compiled alongside the survey, recorded that the parish contained "the site of an old graveyard which gave name to the Townland of Killeen". The word killeen itself is significant: in Irish placename tradition, it typically derives from "cillín", meaning a small church or burial ground, often one used for the interment of unbaptised infants or others excluded from consecrated ground. Whether that applies here is unknown, but the name alone preserves the memory of a burial place long after the physical evidence has gone. A small rectangular paddock, roughly 50 metres north to south and 15 metres east to west, associated with a nearby farmyard and lying to the east of the map notation, has been proposed as the likely location. Both the paddock and the farmyard have since been levelled into the surrounding pasture, though the eastern boundary of the paddock has survived as a field boundary, one of those unassuming lines in the Irish countryside that turns out to be older than it looks.