The ruined structure known as Kenny Church appears to have begun its life as a medieval nave and chancel church, then undergone a peculiar late medieval transformation: the chancel, the eastern liturgical section of the building, was converted into a tower house, the kind of fortified residential structure common across Ireland from the fourteenth century onwards. The nave, meanwhile, was allowed to collapse until only a low earthen platform, roughly 11.8 metres east to west and 6.9 metres north to south, marks where it once stood. The result is a building that changed its function entirely without ever quite losing the evidence of what it had been before.

The tower itself survives to a height of five to six metres and is constructed from undressed limestone laid in irregular courses, bonded with a rough mortar. Its entrance, a pointed archway in the centre of the west wall, may originally have been the chancel arch separating the two sections of the church, repurposed as a doorway when the conversion took place. Inside, a spiral staircase in a circular turret once gave access to the upper floors, though this has been partially blocked. The ground floor retains the springing of a stone barrel vault, a curved stone ceiling characteristic of tower houses, and traces of the wicker centring used as temporary support during its construction are still visible. Putlog holes, the sockets left in walls where timber scaffolding or internal floors were fixed, suggest there was a loft level below the vault. A small projecting turret at the south-east corner, now entirely obscured by ivy, may have served as a garderobe, a medieval latrine built into the wall of a tower. The site sits at the western end of a ridge in undulating pasture and commands good views in all directions, a placement that makes obvious sense for a fortified structure. By 1837, the Ordnance Survey recorded it as a ruin within a graveyard; a later map from 1913 shows the distinctive L-shaped outline of nave platform and tower that visitors can still read in the landscape today. Notably, no church appears at this location on the seventeenth-century Down Survey map of Mullingar parish, which raises quiet questions about when exactly the building passed out of use and memory.