Built by the O Donnell chieftains in the 15th century on the river Eske at the centre of Donegal Town. Rebuilt in Jacobean style in 16th century by Sir Basil Brooke after Hugh O Donnell burnt it to the ground rather than let the castle fall to enemy hands. Information panels chronicle the history of the castle and guided tours are available. The castle opens each season from mid March to the end of October. Donegal (Irish, Dún na nGall), translates as Fort of the Foreigner possibly coming from a Viking fortress in the area destroyed in 1159. However, due to hundreds of years of development, no archaeological evidence of this early fortress has been found. The elder Sir Hugh O’Donnell, wealthy chief of the O’Donnell clan, built the castle in 1474. At the same time, he and his wife Nuala, built a Franciscan monastery further down the river. A local legendtells of a tunnel connecting the two but no evidence for this has been found. The castle was regarded as one of the finest Gaelic castles in Ireland. In 1607, after the Nine Years war the leaders of the O'Donnell clan left Ireland in the Flight of the Earls. In 1611 the castle and its lands were granted to an English Captain, Basil Brooke. The keep had been severely damaged by the departing O'Donnells to prevent the castle being used against the Gaelic clans but was quickly restored by its new owners. Brooke also added windows, a gable and a large manor-house wing to the keep, all in the Jacobean style. The Brooke family owned the castle for many generations until it fell into a ruinous state in the 18th century. In 1898 the then owner, the Earl of Arran, donated the castle to the Office of Public Works