This rectangular fortress, measuring 10.4 metres east to west and 9 metres north to south, was constructed from roughly coursed limestone rubble with larger tooled blocks forming the corners. According to historical records from 1862, the castle and much of the surrounding townland formed part of the see-lands of the Bishopric of Ossory. The structure itself was commissioned by David Hackett following his appointment as Bishop of Ossory in 1460, making it both a defensive stronghold and an ecclesiastical property.

The castle's defensive features reveal the turbulent nature of 15th-century Ireland. Entry was gained through a now broken doorway in the western wall at ground level, where visitors would pass through a lobby overlooked by a murder hole; a grim reminder of the tower's military purpose. A narrow mural staircase, just 0.8 metres wide, spirals upward from the northwest corner, winding through the northern, western and southern walls whilst being illuminated by simple arrow loops. The first floor, accessed via a pointed doorway, features another murder hole in its stair lobby, whilst the ground floor received light through four single windows strategically placed in the walls.

The upper chambers tell a story of both comfort and security. The second floor, the castle's principal chamber, boasts an elegant two-light ogee-headed window in the north wall complete with window seats, alongside a shouldered sandstone window to the west. Though only the flue remains, a fireplace once warmed the southern wall, flanked by wall cupboards that provided storage throughout the room. The third and fourth floors, originally supported by timber beams resting on substantial stone corbels, contained additional living spaces with their own windows and storage alcoves. The fourth floor features a particularly intriguing L-shaped mural passage, accessed through the western wall and running through the castle's thick walls. Evidence suggests a fifth storey once crowned the structure, though the parapet has long since crumbled away.