The catch is that nobody is quite sure where. Recorded observers noted its presence in the nineteenth century, but its precise location has never been pinned down with any confidence, leaving it in that particular category of Irish ecclesiastical sites that are simultaneously documented and lost.

The church was identified in the nineteenth century, with the findings later referenced by Turner in 1983 and by P. Healy in 2004. Beyond its position on the northern slope of the hill, the surviving record offers little: no dedication, no dimensions, no account of what the structure looked like when it was seen. Small rural churches of this kind were once scattered across the Irish landscape, often serving early Christian communities long before the parish network consolidated around larger buildings. Many were simple single-cell structures, built from local stone without mortar, and they have a tendency to dissolve back into the hillside over centuries, especially in upland terrain where field clearance and turf-cutting gradually redistribute loose stonework. That process seems to have advanced considerably at Kilmashogue before anyone thought to measure or map what remained.

Kilmashogue Mountain sits within the Dublin Mountains and is accessible from the Kilmashogue Lane car park off the R113 between Rathfarnham and Killakee, a road that also serves Massey's Wood and the broader network of Coillte forestry trails. The northern slope is rough going in places, without a clear marked path leading to any ecclesiastical feature, which is partly because there is no confirmed point of interest to mark. Visitors walking the hill might watch for anomalous arrangements of stone low in the vegetation, or slight earthwork irregularities that can sometimes indicate where a small structure once stood, but it would be honest to say that the church at Kilmashogue currently exists more firmly in the footnotes of two academic texts than it does on the ground.