Dunbeacon Castle, Dunbeacon, Co. Cork
The fragmentary ruins of Dunbeacon Castle stand on the southern shore of Dunmanus Bay in County Cork, where an earlier coastal promontory fort once protected this strategic position.
Dunbeacon Castle, Dunbeacon, Co. Cork
What remains today is a portion of the tower house’s northern section; the eastern wall stretches for 5.5 metres whilst a small section of the northern wall extends just 2.2 metres, both rising to an impressive three storeys in height. Visitors can still make out traces of the vault that once covered the first floor, its axis running north to south through the structure.
This castle served as a stronghold for the O’Mahony clan, with local tradition crediting its construction to Donall O’Mahony around 1460. The tower house’s history reflects the turbulent politics of medieval Ireland; the O’Mahonys themselves burnt the castle following the Desmond confiscations, preferring to destroy their own fortress rather than see it fall into enemy hands. Despite this act of defiance, English forces eventually seized control of the ruins after the fall of Dunboy Castle in 1602, marking another chapter in the complex story of Irish resistance and English expansion.
Today, these weathered stone walls offer a tangible connection to Cork’s medieval past, standing as a monument to the O’Mahony clan’s former power and the contested nature of Ireland’s coastal defences. The site combines the remains of both the prehistoric promontory fort and the later medieval tower house, creating a palimpsest of defensive architecture that spans centuries of Irish history.