What remains at Cahernarry, set on elevated ground with a large quarry cutting into the landscape to the west and north, is a fragment of a medieval belfry and the tower of a post-1700 Church of Ireland building, both occupying the northern quadrant of a sizeable burial ground. The medieval tower, which stood around 4.87 metres high as of 1840, is the more arresting survivor. Its external walls carry putlog holes, the small sockets left behind when the timber scaffolding used during construction was removed, and these are the only architectural features now legible on the north, south, and west faces.

The site has a long and somewhat tangled administrative history. The antiquary Thomas Johnson Westropp, writing in 1904 and 1905, traced the place name through a series of Latin and anglicised forms: Keyrnedyn, Carnarthy, Karnathie, and eventually Cathairnaraidhe, which the scholar John O'Donovan translated as "Fort of Naraidhe," suggesting a pre-ecclesiastical significance to the site. It appears in a charter of King John dated 1207, and again in 1253 when Carnarthy was restored to Bishop Bobert by Athassell, the Tipperary priory that held considerable influence across the region. By 1320, the parish had become the subject of a legal dispute over Roger Bagod's right of presentation, a term referring to the right to nominate a clergyman to a parish living. The church was dedicated to St Nicholas by 1410. Nearby, a holy well called Tobersenan is recorded, and close to the later Catholic church, built in 1810, lies the vault of the Howley family.

The graveyard remains in use and is accessible, situated on ground that gives wide views over the surrounding County Limerick countryside. Visitors looking closely at the surviving medieval tower will notice how little decorative stonework was left once the scaffolding came down; the putlog holes are essentially all the evidence of the building process that time has preserved. The juxtaposition of the two towers, one medieval and one post-Reformation, in such proximity makes the layering of ecclesiastical history here unusually visible in physical terms.