Rising to approximately 18 metres in height, this imposing structure commands sweeping views across the surrounding countryside, though time has not been entirely kind to it; the southeastern corner, which once housed the stairway, has long since collapsed, leaving the tower incomplete. The castle measures 10.8 metres from east to west and 8.7 metres north to south, with substantial walls some 2 metres thick that speak to its defensive purpose.

The architectural details reveal much about medieval castle construction in Ireland. A vault once spanned the second floor, now clearly visible through the gap where the southeastern angle once stood. Most of the windows are narrow defensive slits, typical of such fortifications, though the north wall features a notably larger window with a distinctive pointed head. The main entrance, a quadrangular doorway, sits in the western wall alongside an interesting fireplace feature that projects from the interior wall and runs its entire length. In the fields to the north and west, several mounds suggest additional defensive earthworks that may have once protected the castle’s approaches.

The castle witnessed dramatic events during the turbulent 16th century, as recorded in the Annals of the Four Masters. In 1577, a fierce dispute erupted between Gerald Fitzgerald, Earl of Desmond, and Thomas Fitzmaurice of Kerry over control of the castle. The Earl succeeded in capturing Ballymacaquim, but the victory came at a terrible cost; the young abbot O’Torna, who had sided with the Earl, was shot dead in the castle doorway just after the Earl’s forces had secured the building. Many of Fitzmaurice’s men were killed or drowned that day, and the conflict raged on until peace was eventually brokered. As part of the settlement, Ballymacaquim was returned to Fitzmaurice along with prisoners and substantial compensation in cattle and horses, underlining the castle’s strategic and symbolic importance to the family.