Around it, on the north-east, south, and north-west sides, a low earthen scarp, barely half a metre high in places, traces the arc of an ecclesiastical enclosure roughly a hundred to a hundred and twenty metres in diameter. Such enclosures are the characteristic footprint of early Irish monastic and church sites, circular or roughly circular boundaries that once marked out sacred ground from the surrounding landscape. Here, the eastern portion of that boundary has been cut away by a road and car park, so the surviving scarp is fragmentary, easy to overlook if you do not know what you are looking at.

The church that once stood inside this enclosure is long gone. According to John O'Donovan, writing around 1840, the parish church of Killan was pulled down circa 1835, leaving no visible trace within the subrectangular graveyard that remains in its place. O'Donovan was one of the principal scholars behind the Ordnance Survey's parish memoirs of Ireland, and his observations from that period are a valuable record of what was already disappearing from the landscape. By the time he noted the demolition, the building had only just been removed, yet even then nothing of it survived above ground. The graveyard itself continues in use, enclosed within its own later boundary, the earlier and far larger enclosure curving silently around it.

About a hundred and sixty metres to the south, St Anne's Well is still venerated, maintaining a continuity of practice that outlasted the church and its enclosure both. Holy wells in Ireland frequently predate the Christian structures associated with them and often retain local devotion long after those structures have vanished. The well at Killann is a reminder that the significance of a place is not always carried by its most visible monuments.