At Russagh in County Westmeath, the boundary of a quiet rural burial ground preserves, in modified form, the curved outline of what may once have been an Early Christian ecclesiastical enclosure, the kind of roughly circular or D-shaped earthen bank that monks and clerics of the early medieval period raised around their church settlements to mark sacred ground and define community space.

The site is linked to St. Caemhan Brec, Bishop of Ross-Each, whose feast day falls on the 14th of September. He appears in two early Irish martyrologies, the Félire of Óengus and the Martyrology of Tallaght, where the place is referred to as Caille Fhallamhain, meaning Fallon's wood or the wood of the chief professor, a name that hints at a learned ecclesiastical community in the early medieval period. By 1837, when the Ordnance Survey was compiling its Name Books for the parish of Russagh, the old parochial church had been reduced to a fragment of one wall. The surveyor noted, with a certain bluntness, that the graveyard presented nothing of interest except its situation within an earthen rath, using the word rath to mean a circular earthen enclosure. That observation is now more significant than the surveyor perhaps intended. The D-shaped boundary visible on the 1837 Ordnance Survey six-inch map, described by researcher Swan in 1988, follows a curving line consistent with an Early Christian enclosure. Sometime between 1837 and 1911, that earthen bank was replaced by a stone wall, and the revised six-inch map from the latter year shows a more regularised, sub-rectangular enclosure. The original curve of the ground was, in effect, squared off, making what survives a palimpsest, an older form partially rewritten by later hands.