The wall follows a semi-oval line, and it is precisely that shape, rather than anything visible above ground, that has prompted the suggestion that something older may lie beneath the surface of the site.

The semi-oval or D-shaped outline is a form associated with Early Christian ecclesiastical enclosures, the curved boundaries that once surrounded early medieval churches, often monastic in character, across Ireland. These enclosures, typically dating from roughly the sixth to the twelfth centuries, were defined by earthen banks, ditches, or stone walls and frequently left their imprint on the landscape long after the religious community that made them had vanished. At Rathgarve, the graveyard wall may simply be following, consciously or not, the line of such an earlier boundary. Researcher Liam Swan noted the significance of this form in 1988, suggesting the possibility of an Early Christian enclosure on this basis. The evidence, however, remains tentative: aerial photography of the site has revealed no trace of an earlier enclosure, leaving the curved wall as the only physical clue.