A fragment of wall standing four metres high in a Kildare graveyard has generated more questions than it has answered for anyone trying to pin down what, exactly, once stood at Oldcarton. The surviving structure is modest enough: a stretch of ivy-covered limestone masonry roughly two and a half metres long and a metre thick, believed to represent the eastern gable of a former church. But whether that church was simply a chapel of ease, a term for a secondary place of worship built to serve parishioners who lived too far from the parish church, or the remnant of something far less common, a nunnery, remains genuinely unresolved.

The 1654 Civil Survey identified the building as a chapel of ease, which would make it unremarkable by the standards of post-medieval Irish ecclesiastical remains. A later Ordnance Survey letter, recorded by Herity in 2002, offers a different reading altogether, describing the wall as belonging to a nunnery that formerly occupied the site. That local tradition of a female religious house is given a little indirect weight by the presence of a holy well, a Nun's Well, located approximately 240 metres to the south-southwest. Holy wells associated with particular communities or dedications often preserve the memory of institutions that have otherwise vanished entirely from the documentary record. Even so, the standard scholarly reference work on Irish medieval religious houses, compiled by Gwynn and Hadcock in 1970, records no nunnery at this location, leaving the oral and cartographic tradition without corroboration from the written sources that survive.