The circular form of that wall is the kind of detail easy to walk past without a second thought, yet it may preserve the outline of an early medieval ecclesiastical enclosure, the roughly circular or oval boundary that once defined the sacred precinct of an early Irish church site.

The possibility was first noted by Swan in 1988, who observed that the graveyard's boundary follows a suspiciously rounded course, consistent with the type of enclosure commonly associated with early Christian foundations in Ireland. What makes Clonarney particularly arresting is the presence of castle ruins standing within the graveyard itself. The juxtaposition is not so unusual in Irish archaeology as it might first appear; secular and ecclesiastical authority frequently overlapped in the medieval landscape, with castle builders often planting themselves at sites that already carried significance. Here, the two elements, a possible early church enclosure and the remains of a later castle, occupy the same ground, each quietly complicating the other's story.

The circular enclosure form, if it is genuine rather than coincidental, would suggest that religious activity at Clonarney predates the Norman or late medieval period considerably. Early ecclesiastical enclosures in Ireland are often the only surviving trace of church communities that left no standing stonework, their presence legible only in the curve of a field boundary or a graveyard wall that nobody quite got around to straightening.