Originally held by the Lords of Upper Ossory, the castle passed through several hands during the turbulent 17th century, belonging to Gilbert Rawson in 1653 and Edmond Morris in 1691 before William of Orange granted it to Richard and Edward Fitzpatrick in 1696. Though now roofless and partially collapsed, with rubble obscuring much of the ground floor, the tower’s impressive 11.7-metre diameter and nearly 3-metre thick walls still convey its former strength.

The castle’s defensive architecture reveals sophisticated medieval engineering, from the pointed entrance doorway with its yett hole at the east-northeast to the murder hole shaft on the fourth floor. A clever internal layout maximised both security and comfort; visitors entering through the main door had to turn right through a small lobby before accessing the ground floor chamber, whilst a mural staircase spiralling through the northern wall connected all levels. The third floor features a particularly ingenious barrel vault with wicker centring running north-northeast to south-southwest, creating a loft space beneath. Each level served distinct purposes, with gun loops for defence, twin light windows for illumination, and limestone fireplaces appearing from the second floor upwards, including an elaborate example on the fourth floor with chamfered sandstone surrounds and a three-piece lintel with dressed keystone.

Despite centuries of weathering, remarkable details survive throughout the structure. The external limestone render still clings to much of the tower, whilst inside, evidence of the original wooden floors remains in the form of wall offsets and corbels. The upper levels reveal increasingly domestic features; a five-sided second floor chamber with its large rectangular fireplace, later modified with brick piers, and what may have been a garderobe chamber accessed through the eastern wall. At the summit, though the parapet has vanished above the string course, machicolations positioned over the entrance and western side demonstrate the castle’s final defensive measures, whilst a rectangular chimney rising over the southern wall-walk hints at the comfort sought by its medieval inhabitants.