Defended by the Watergate, a postern with two towers by the lake, the castle was built in the 15C by the powerful Maguire family, chieftains of the Fermanagh Clan. The keep is home to the Regimental Museum of the Royal Inniskilling Fusiliers, which displays mementoes relating to the turbulent history of this prestigious regiment. Exhibitions related to the recent archaeological discoveries found on the crannog of Drumclay are held in the rooms giving onto the castle courtyard.