The church measures roughly eleven metres east to west and under five metres north to south, with walls around sixty centimetres thick. A doorway opening survives at the western end of the south wall, though the interior has long since been reclaimed by vegetation and is now inaccessible. By the time the Ordnance Survey mapped the island in 1842, the building was already recorded simply as a church in ruins.

What makes this modest rubble-field quietly significant is what it may represent in terms of age. The Down Survey of the 1650s, one of the earliest systematic land mappings of Ireland, shows no church on Whiddy Island at all, which suggests the building had already fallen out of recognisable use or record by that point. Yet a decretal letter issued by Pope Innocent III in 1199 may reference this very site. The letter mentions a parish called Insscuingi, identified by the scholar Bolster in 1972 as potentially corresponding to this island location. A decretal letter was a formal papal ruling issued in response to a specific query, often concerning disputed ecclesiastical jurisdiction, and their survival in the historical record is relatively rare. If the identification is correct, this unassuming ruin on a small island off the Cork coast was already part of an established parish structure more than eight hundred years ago, long before its walls began to collapse and the nettles moved in.