Its walls are poorly preserved and stripped of any architectural detail, the stonework a rough coursed rubble of local limestone with nothing left to indicate a doorway, a window, or a date. It is the kind of site that rewards close attention rather than a casual glance, a low rectangular outline measuring roughly eleven metres north to south and just over seven and a half metres east to west, modest even by the standards of early Irish ecclesiastical buildings.

The place-name itself carries the main clue to what once stood here. Kiltoom derives from the Irish "cill", meaning a church or monastic cell, a prefix that appears across hundreds of Irish townland names and almost always signals an early Christian foundation, often pre-Norman and sometimes reaching back to the early medieval period. Lough Carra, on whose shore this site quietly sits, is a shallow limestone lake in south County Mayo, known for its marl bed and its unusually clear water. The broader landscape around Ballinrobe and the twin loughs of Carra and Mask contains a dense scatter of early ecclesiastical and archaeological sites, and this ruined church, however reduced, belongs to that wider pattern of early Christian settlement along the lakeshore.