The designation is quietly telling: not the church itself, but the site of it, suggesting that whatever once stood here has long since vanished into the ground, leaving only a footprint, a name, and the question of what it once was.

Rosslee is the kind of place-name that carries ecclesiastical weight in the Irish landscape. Early church sites in Mayo were often associated with minor monastic foundations or with the network of parish churches that spread across the west during the medieval period, many of them simple structures built in stone without mortar, later abandoned during the upheavals of the sixteenth and seventeenth centuries. Without surviving fabric above ground, such sites are frequently identified through earthwork traces, concentrations of worked stone, or the presence of an associated burial ground, which in Ireland often outlasted the building it once adjoined. The townland name Rathnacreeva may itself preserve older layers of meaning, "rath" pointing to an earthen ringfort, the most common type of early medieval farmstead enclosure found across the country, suggesting the area has been inhabited and named for a very long time.