The rectangular enclosure, roughly 70 metres east to west and 40 metres north to south, is bounded by a modern wall, yet within it the fabric of the church itself tells a more complicated story. The building is of two-period construction, meaning it was altered or extended at some point after its original raising, and the chancel, the eastern section of the church reserved for the altar and clergy, may have been added during medieval or post-medieval times. That ambiguity is part of what makes the site interesting: the exact sequence of building remains unresolved.

The church is known as St. Catherine's, and the site has a documented history stretching back to at least 1216, when a church at Killadreenan is recorded as belonging to the diocese of Dublin, a reference cited by Donnelly in 1893. That early thirteenth-century mention places the site firmly within the network of ecclesiastical administration that the Anglo-Norman church was consolidating across Leinster at the time. The church sits on a gentle south-facing slope above a small stream, a setting typical of early Christian and medieval foundations, which were often positioned near water. Among the gravestones, both inside the ruined church walls and in the surrounding ground, several date to the early eighteenth century, giving the site an additional layer that connects the medieval ecclesiastical past to the more recent vernacular tradition of commemorating the dead in carved stone.