Known as Cabra Castle on Rocque’s 1775 map of Thurles, the structure sits roughly 100 metres from the river, its roughly square footprint built from coarsely cut limestone blocks. The builders incorporated a defensive base-batter on three sides, though curiously omitted it from the northwest wall.

Today, only the ground and first floors remain of what was once a much taller fortification. The upper levels have been deliberately removed, leaving an unnaturally flat top where medieval battlements once stood. The Ordnance Survey Letters from 1930 recorded significant alterations even then, noting that the north wall had been completely destroyed and replaced with an external staircase; a dramatic modification that necessitated cutting new doorways through the ancient stonework. The same survey mentioned remnants of what might have been a circular watch tower at one corner, possibly a bartizan that once projected from the northwest angle.

Evidence of the castle’s original defensive perimeter survives in a 22-metre stretch of wall standing about 20 metres north of the tower. Built from roughly coursed limestone rubble and rising 2.5 metres high, this may be all that remains of the bawn wall that once enclosed the castle grounds. The wall features a base-batter on its southeast face and appears to have originally connected to the tower house itself, meeting the northwest wall slightly off-centre. Time hasn’t been kind to this ancient barrier; the northwest face bulges precariously despite the support of two large buttresses, whilst at its northeast end it disappears into the foundations of a more recent house.