The history of Enniskillen Castle spans more than five centuries. The oldest building within the complex is the Keep, a 15th century stronghold of the Gaelic Maguire chieftains, captured by the Crown forces during the Elizabethan wars.

The Castle was rebuilt in the early 17tn century while the Watergate, with its distinctive twin turrets was also built at this time.

The Castle became a military barracks in the late 18th century and the surrounding barracks were erected between 1825-30. Enniskillen Castle houses two museums and the Royal Inniskilling Fusiliers Museum.