While local tradition credits its construction to one Carbery O’Shea, the castle’s history is more firmly tied to the powerful MacCarthy clan. Records suggest some form of residence existed here as early as 1398, when the annals note Taghd Mac Carthaigh’s death at Ballycarbery, though the current ruins date from later. The existing structure is likely the ‘castle of Valencyen called Ballycarborow’ mentioned in documents from 1569, and by 1594 it was recorded as a MacCarthy More stronghold. During the sixteenth century, the O’Connells occupied the castle as MacCarthy wardens, with Morgan O’Connell of Ballycarbery notably becoming High Sheriff of Kerry under Elizabethan rule.

The castle changed hands in 1596 when Sir Valentine Browne took possession following the death of Daniel MacCarthy More, Earl of Clancar. Its military life came to an end during the Cromwellian period when parliamentary forces deliberately damaged the structure whilst fortifying Valencia Harbour in 1651;52. What remains today is a substantial rectangular tower house measuring 22.5m by 12.9m, complete with an attached turret at its northeast corner. The ivy;covered walls, built from roughly coursed blocks and rubble laid in lime mortar, rise through three storeys with vaults supporting the first floor level. The building’s defensive features include a round;headed entrance doorway positioned off;centre in the north wall, complete with drawbar sockets and evidence of a portcullis groove served from the second floor.

The interior layout reveals the sophisticated planning typical of fifteenth;century Irish tower houses, which architectural historian Harold Leask dates this example to. The ground floor was divided into three transverse chambers, each roughly 7.15m by 4.95m, with pointed vaults constructed on wicker centring supporting the first floor above. Two separate mural staircases provided circulation; one ascending from the entrance lobby, the other beginning in the west ground floor chamber. The second floor housed the castle’s great hall, accessed via these stairs and featuring a series of fine windows with limestone dressings. Though much of the south and east walls were destroyed during the seventeenth;century slighting, and further masonry was removed in the early twentieth century, the remaining structure offers remarkable insight into the defensive architecture and domestic arrangements of a major Gaelic lordship’s stronghold.