Historical records from 1574 identify this stronghold as 'Bally McDuffe' castle, then held by one Redmund McHubert. The rectangular tower, measuring roughly 10.4 metres northeast to southwest and 9 metres northwest to southeast, rises at least four storeys high, though little remains of the uppermost level's side walls.

The castle's defensive architecture reveals the paranoia and practicality of its medieval builders. The original entrance, centrally positioned in the northeast wall, leads visitors into a lobby overlooked by a murder hole; a sobering reminder of the violent times in which it was built. From here, doorways branch off to a spiral staircase in the north corner, a guardroom to the south, and the main ground floor chamber. The tower incorporates several stone vaults between floors, with their original wicker centring still visible in places. Subsidiary chambers nestle beside the main rooms on the first floor and between the second and third levels, whilst fireplaces warm the southeast walls of both ground and second floors, though the ground floor fireplace appears to be a later addition, inserted into what was once a window embrasure.

Perhaps most intriguing are the castle's hidden features: a garderobe in the west corner, accessed via a passage running along the northwest wall from the stairs, with its exit chute still visible at the base of the southwest wall. Even more mysteriously, an intramural passage opens from a window embrasure on the second floor's southwest wall, running southeast and potentially leading to a concealed chamber hidden within the thickness of the vault arch below. The surviving windows, featuring flat, round, or ogee-headed single lights, punctuate the thick walls, whilst a short section of walling abutting the castle's southeast side may be all that remains of an original bawn wall that once enclosed the tower's immediate grounds.