At Kilmacanoge in County Wicklow, the ruined church in the eastern part of the graveyard contains exactly that: a Romanesque-style arch of undressed voussoirs, those wedge-shaped stones that lock an arch together, pushed to one side of the nave's east gable rather than sitting squarely at its centre. Whether this reflects a later insertion, a structural compromise, or something else entirely, it gives the building an quietly asymmetric character that its ivy covering only partly disguises.

The site appears in the historical record as 'Cell Mothenoc', a name documented as far back as 1173, and it was already a ruin when the nineteenth-century scholar John O'Donovan described it in the Ordnance Survey Letters. What survives is a rectangular structure of roughly coursed, undressed sandstone with well-dressed granite quoins at the corners, comprising a nave and the partial remains of a chancel. The west gable of the nave stands to something close to its original height of around five metres and retains a small rectangular window at first-floor level; the lower section of its inner face is masked by a row of tall eighteenth-century graveslabs leaning against the wall. The north wall is largely intact, while the south wall has been partly robbed out, its stones likely taken for later building work nearby. Along the line of that missing south wall lies a bullaun stone, a roughly hollowed boulder of the kind found at early ecclesiastical sites across Ireland, often associated with ritual or practical use. Of the chancel, only the east gable remains standing, containing a narrow limestone window set within a broad, gently splaying embrasure; the top and sill of the window have been removed, leaving a fragment suspended between more complete stonework on either side.