Built from sandstone with limestone surrounds and cut-stone quoins, this medieval stronghold measures approximately 8.6 metres from northeast to southwest, with walls an impressive 2.15 metres thick. Though farm buildings now abut its northeastern and southeastern faces and ivy obscures much of its exterior, the tower still reveals fascinating architectural details, including a stone plinth that projects 20 centimetres from its base and a slight batter at ground level.

The castle’s main entrance, a round-headed doorway decorated with vertical punch-tooling within margins, sits off-centre on the northwest wall near the western angle. This leads to a lobby that once connected to various chambers via a now partially collapsed vaulted passage. The interior layout follows the typical pattern of Irish tower houses: the ground floor chamber features three single-light windows, whilst a spiral staircase in the northern angle once provided access to upper floors, though it’s now badly damaged beyond the first floor. Each level had its own amenities; L-shaped garderobe chambers with chutes for waste disposal were cleverly integrated into the walls, and the second floor appears to have contained a fireplace in the southwest wall, evidenced by a broken-out embrasure with putlog holes for supporting a lintel.

By 1654, when the Civil Survey recorded it as ‘an old castle out of repayre’ belonging to Thomas Magher of Bollybane, the structure had already seen better days. Yet intriguing features remain, including small mural chambers accessible from the spiral stairs at multiple floor levels, and a sophisticated water system that once connected to a well about 100 metres southeast of the tower. According to a 1943 survey, an underground drain led to two stone reservoirs beside the castle, with a surface drain running along the castle wall; a system that would have provided the inhabitants with a reliable fresh water supply. The floors were constructed using different methods: a vault supported the first floor, whilst the second and third floors rested on timber beams carried on corbels, with a barrel vault crowning the third floor above.