Castlederg Castle

Derg Castle stands on the north bank of the River Derg in the town of Castlederg, County Tyrone. Its name comes from the Irish Caisleán na Deirge, meaning ‘Castle on the Derg’. The site is a Scheduled Historic Monument managed by the Northern Ireland Department for Communities. The earliest record of a castle here dates from 1497, when an O’Donnell stronghold was attacked and taken by the O’Neills. By the early 16th century the castle had changed hands several times during conflicts between these clans. The castle was rebuilt in 1610 under the Plantation of Ulster for Sir John Davies, Attorney General for Ireland. He turned it into a bawn with three open flankers and built a seven-mile causeway to Kirlish Castle. In 1619 Captain Nicholas Pynnar surveyed both castles and noted their strength. During the 1641 rebellion a small Scottish settler garrison held out against a much larger force led by Sir Phelim O’Neill. In 1689 the castle surrendered to James II’s troops after a promise of safety. Today only parts of the walls and flankers remain, much eroded by the river. The tower house itself has vanished, leaving low stone fragments on the south side. The ruins stand within the town, close to the riverbank. Visitors can walk around the remains and see how the river has shaped the site over centuries. The location offers a quiet spot to imagine the castle’s past as a place of refuge and conflict.