This keepless enclosure castle, likely built by Maurice de Rochford in the late 1200s, originally consisted of a square ward surrounded by curtain walls with circular towers at each corner. Today, only fragments remain; the southwest curtain wall stretching 38 metres, the south and west towers, and a portion of the northwest wall measuring nearly 30 metres. The rest was demolished around 1696, its stones repurposed to build the now-vanished Kilbolane House, where the Bowen family traded castle life for more comfortable Georgian living quarters.

The surviving towers reveal intricate defensive features and later modifications. The west tower’s ground floor contains a circular chamber with a flattened vault ceiling, accessed through an eastern doorway from within the ward. A curving mural staircase leads to a hexagonal first-floor chamber topped by a high pointed vault, possibly a 15th-century addition when the FitzGibbon family extensively renovated the castle. The south tower tells a similar story of adaptation, with its circular chambers connected by spiral stairs and passages built into the thick curtain walls. Evidence suggests this tower was refitted as living quarters in the late 17th century, complete with garderobes, window seats, and what appears to have been a murder hole above the entrance passage.

The castle changed hands several times throughout its history, passing from the de Rochfords to Thomas mac Shane FitzGibbon in the late 14th century, whose descendants held it until 1587. After a brief period under Hugh Cuffe’s ownership, it returned to the Gibbon family through Helena Gibbon’s marriage to William Power of Waterford. The Powers retained Kilbolane until the mid-17th century, by which time the age of castles was drawing to a close. Today, protected as a National Monument in State Guardianship, the ruins stand surrounded by remnants of their defensive moat, which still reaches depths of over two metres in places, whilst a modest well house in the centre of the ward marks where the castle’s water supply once sustained its inhabitants.