An aerial photograph taken in the summer of 1989 revealed a crop-mark, the ghostly outline that buried or levelled features leave on growing vegetation, tracing a circular enclosure roughly 90 metres in diameter. The present graveyard occupies only a fraction of that original circuit, tucked into its south-east quadrant like a small room surviving inside a demolished house.

The enclosure is believed to mark the site of Cill Séanacháin, meaning Seanchan's church, a dedication recorded by the local historian Power in 1923. Ecclesiastical enclosures of this type, roughly circular earthworks that once defined the boundary of an early Irish monastic or church settlement, were a common feature of the early medieval landscape, though most have been reduced over centuries of agriculture to little more than faint traces. At Ballinaltig, a curving earthen bank still standing to an external height of about 2.5 metres survives on the south side of the graveyard and may represent the best-preserved remnant of that original boundary. By 1935, when the Ordnance Survey mapped the area at six inches to the mile, the arc of bank to the north had already been absorbed into the field fence system, its ecclesiastical origins effectively erased by practical use. As for Seanchan himself, the name is tantalising and the dedication is old, but as Power noted with some candour, there is nothing by which we can identify this particular Seanchan. He may have been a locally venerated figure whose memory faded before any written record was made.