At the eastern end of a church in Carbury, where the altar or chancel would traditionally have stood, something else now occupies the space: a large family mausoleum, roughly 7.7 metres long and just over 3 metres wide, built by or for the Colley family sometime in the eighteenth century. It is the kind of arrangement that quietly inverts the expected order of a sacred building, placing the commemorative claims of one family at the liturgical heart of the structure.

The Colleys were a prominent Anglo-Irish family with strong connections to County Kildare, and their presence here is marked by at least three surviving plaques. Two are inside the mausoleum itself: one dated 1710, bearing the Colley name, and a second whose inscription has become illegible with time. A third Colley plaque, dated 1705, is mounted separately on the church wall. Taken together, the plaques span at least the first decade of the eighteenth century, suggesting the mausoleum was constructed around that period as a deliberate dynastic statement, absorbing the east end of an older church into a private monument to the family dead.