Carrickabraghy Castle was one of a network of castles built to defend and protect the Inishowen lands belonging to the O’Doherty clan in the late 1500’s. It was built using sea-sand mortar on a strategic rocky promontory. This was a perfect hideaway as ‘Doagh Island’ is an island within a peninsula. It was occupied by Phelemy Brasleigh O’Doherty and was later chosen by Cahir O’Doherty to plan his famous revolt that led to the Flight of the Earls in 1607. Further back in time between 834 and 1200 this location, according to the Annals of the Four Masters, was the site where the McFaul Clan resided. The McFaul’s were a powerful sept of the ruling O’Neill Chieftains of Ulster.