Donegal Castle is located in the centre of the county town. The tower house was built by Red Hugh O’Donnell, chief of the O’Donnell clan, in 1474. The Gaelic family ruled the Kingdom of Tir Chonall (the present-day County Donegal) between 1200 and 1601.

The castle was set alight by the fleeing O’Donnells in 1601 to prevent its use by the English, who defeated them during the Nine Years War. However, the castle’s new lord, English captain Sir Basil Brooke, repaired the damage and also added a Tudor manor house.