Not a wall, not a foundation course, not a scatter of cut stone. The site is recorded as a killeen, a term used in Ireland for a small, often unconsecrated burial ground, frequently associated with unbaptised infants or with early Christian enclosures that fell out of formal use. Whatever ecclesiastical structure may once have stood here has left nothing visible for a visitor to read in the landscape.

The antiquarian Thomas Johnson Westropp, writing in 1904 to 1905, gathered what documentary traces existed. The name appears as Killonayn in a fiant of 1601, a type of administrative warrant issued under the Irish chancery, and the place is marked on the Down Survey, the seventeenth-century land mapping project carried out following the Cromwellian conquest. Westropp connected the dedication to Lonan, son of Erc, of the Uí Fidgeinte, a Munster people whose territory covered much of this part of Limerick. According to a life of St Patrick, Lonan was a disciple of the saint and is said to have dwelt to the east of Singland around 440 AD, near a place called Mullach Cae, south of Cam Feredaig. The scholar John O'Donovan, without citing his authority, offered an alternative reading, suggesting the name derived from Adamnán rather than Lonan, which Westropp noted but did not endorse.

The killeen sits close to Killonan railway station, which at least makes the general area straightforward to locate. There is nothing to see in the conventional sense; the interest lies precisely in the absence. Anyone visiting would be looking at a graveyard where the ground itself holds the only remaining evidence of an ecclesiastical presence that once carried a name recorded in sixteenth-century legal documents and possibly connected to the earliest generations of Irish Christianity.