For some time this feature was read as the outer boundary of an Early Christian monastic enclosure, roughly 145 metres in diameter, thought to belong to a monastery of considerable antiquity. The reality turns out to be more layered than that, and arguably more interesting for it.

The site takes its name from Kilbixy, or Ceall Bhigsighe, the church of St Bigseach, a figure whose festival was marked on both the 28th of June and the 4th of October, and who was associated with St Brigid of Kildare. The monastery here was recorded as early as the medieval period, and scholars had long supposed that the curving ditch preserved the outline of its original enclosure, a common feature of Early Christian ecclesiastical sites in Ireland, where a roughly circular boundary ditch or bank would have defined the sacred precinct of a monastic community. However, the ditch is now understood to be a post-medieval fosse, a deliberately dug landscape feature of the kind sometimes called a ha-ha, which allowed uninterrupted views across grounds without the intrusion of a visible wall or fence. Its construction was described in the 1793 edition of the Anthologia Hibernica, a Dublin periodical of the period, placing it firmly in the era of the church building it accompanies rather than in the age of St Bigseach. The confusion is understandable; early monastic enclosures and designed landscape features can leave strikingly similar traces in the ground.

What the graveyard did yield, more unambiguously, was a sandstone cross-slab of Early Christian date, uncovered during a clean-up scheme in 1980. Cross-slabs are among the more common grave markers of the early medieval Irish church, typically incised with a simple cross rather than carved in relief, and this example is now displayed inside the Church of Ireland building on the site, a small Early Christian object quietly outlasting centuries of interpretation and misreading around it.