This rectangular limestone fortress, measuring roughly 14.7 by 9.4 metres, showcases the exceptional craftsmanship of its builders through its coursed limestone blocks, sturdy quoins, and distinctive base-batter. The tower’s defensive features are immediately apparent; yett-holes above the southern entrance once secured a heavy iron gate, whilst a guardroom to the east, complete with a musket-loop in the corner, provided an additional layer of security for those within.

The interior layout reflects the typical arrangement of an Irish tower house, with the ground floor divided into two barrel-vaulted chambers connected by a doorway in the partition wall, though this passage has since been blocked. A narrow doorway in the eastern wall conceals mural stairs that wind upward to the upper floors, where the living quarters would have been located. The first floor, now dominated by a large concrete pit, once featured a substantial fireplace in the south wall, whilst the second floor retains a particularly fine example with chamfered jambs and corbelled mantle supports, suggesting this was likely the principal chamber of the castle.

What sets Ballymackey apart is the quality of its architectural details; many windows feature elegant semi-elliptical or ogee-headed designs with hollow spandrels and hood-mouldings, whilst the interior stonework displays decorative tooling that points to construction in the late sixteenth or early seventeenth century. These refined touches suggest the castle was built for a family of some means and status, keen to display their wealth and sophistication even whilst maintaining the defensive capabilities essential to survival in those turbulent times.