Donegal Castle
Donegal Castle is the town's major national monument. It was built in c.1470 as a four-story tower house in the Norman style by the O'Donnells, and extended during the 17th century Plantation Era by Sir Basil Brooke who added gables, mullioned windows, and a Jacobean wing. The castle was completely restored and opened to the public in 1996, and is furnished inside with authentic period pieces. Open daily from mid-March until the end of October and some weekends leading up to Christmas.