Built around 1586 when the lands passed to the Shortall family, this four-storey limestone fortress tells a turbulent story of rebellion, confiscation, and changing fortunes. The castle’s origins are tied to the dramatic events of 1566, when Thomas Comerford of Ballymack saw his estates, including Kilbline, seized after being attainted for rebellion. Following a series of temporary leases, the property eventually found its way back to Henry Comerford in 1586, only to quickly transfer to the Shortalls, who likely commissioned the tower house that same year.

The castle itself is a sturdy rectangular structure measuring 11.1 by 8.6 metres, built from roughly coursed limestone rubble with a harled exterior. Its defensive features include a machicolation protecting the original north entrance, multiple gun loops, and a round bartizan on the southwest corner. Inside, the tower reveals the typical arrangement of an Irish tower house: storage and guard rooms on the ground floor, a vaulted first floor, and the main hall on the second floor, complete with a fireplace dated 1580. The upper floors housed private chambers and a garderobe, whilst the attic level provided access to a wall walk and a unique mural chamber running along the western wall, topped by a look-out post that served as a fighting platform.

By the 1650s, the Down Survey recorded Kilbline as ‘a castle in good repaire and a pigeon house’, but Cromwell’s forces soon confiscated the Shortall estates. The Restoration brought new owners, including the Duke of York, and by the 18th century, the castle had passed through the hands of Ralph Gore to the Candler family. The Ryans, who occupied it from the 19th into the 20th century, adapted the medieval structure for modern use, converting floors into storerooms whilst maintaining a panelled sitting room within the tower. Today, with its farmhouse attachment and various modifications, including wooden stairs replacing stone ones and a corrugated iron roof at attic level, Kilbline Castle represents centuries of continuous occupation and adaptation, from medieval stronghold to working farm building.