The castle’s most dramatic moment came in April 1600, when Owney O’Moore held the Black Earl of Ormond prisoner within its thick limestone walls; a bold act during a turbulent period of Irish resistance. The earliest recorded owner was Donal Fitzpatrick, described as a ‘gentleman’ who received a pardon in 1566, suggesting he may have been involved in one of the period’s many rebellions against English rule.

The tower house measures approximately 10 by 12 metres and rises through five storeys, its walls an impressive 2.4 metres thick, built from randomly coursed rubble with substantial limestone quoins at the corners. The defensive architecture includes a base batter for structural strength, whilst the entrance on the north wall leads to a stairwell tucked into the northeast corner. An unusual feature is the barrel vault with wicker centring that spans the third floor; most tower houses place their stone vaults over the ground floor for defensive purposes, making this arrangement somewhat distinctive. The castle’s defensive capabilities are evident in details like the musket loop beside a first-floor window and the remains of a bawn wall that once extended north and west from the tower.

The interior reveals the domestic arrangements typical of a prosperous Irish tower house. Mural passages at the first and second floors lead to a garderobe in the northwest corner, whilst a fireplace on the second floor provided warmth to the main living quarters. The windows vary between single and twin lights, with particularly fine examples of round-headed windows constructed from punched dressed limestone in the west wall. Wooden floors once rested on corbels projecting from the walls, and there’s evidence of small chambers in the southwest corner, now destroyed, that would have provided additional living or storage space. A doorway at second-floor level in the east wall connected the main chamber to a southeast room, showing how the castle’s residents moved between spaces in what was once a bustling defensive residence overlooking the river valley.