Dunseverick Castle is located on the peninsula near the small village of Dunseverick and the Giant's Causeway.
Saint Patrick is recorded as having visited Dunseverick castle in the 5th century AD, where he baptized Olcán, a local man who later became a Bishop of Ireland. The original stone fort that occupied the position was attacked by Viking raiders in 870 AD.
In the later part of the 6th century AD, this was the seat of Fergus Mor MacEirc (Fergus the Great). Fergus was King of Dalriada and great-uncle of the High King of Ireland, Muirceartaigh (Murtagh) MacEirc. It is the 500 AD departure point from Ireland of the Lia Fail or coronation stone. Murtagh loaned it to Fergus for the latter's coronation in western Scotland part of which Fergus had settled as his sea-kingdom expanded.
The O'Cahan family held it from circa 1000 AD to circa 1320 AD, then regained it in the mid-16th century. Last one to have the castle was Giolla Dubh Ó Catháin, who left it in 1657 to settle in the Craig/Lisbellanagroagh area. Post 1660 they use the anglicised name McCain/O'Kane.
The castle was captured and destroyed by General Robert Munro in 1642 and his Cromwellian troops in the 1650s, and today only the ruins of the gatelodge remain. A small residential tower survived until 1978 when it eventually surrendered to the sea below.
References:The Château de Foix dominates the town of Foix. An important tourist site, it is known as a centre of the Cathars. Built on an older 7th-century fortification, the castle is known from 987. In 1002, it was mentioned in the will of Roger I, Count of Carcassonne, who bequeathed the fortress to his youngest child, Bernard. In effect, the family ruling over the region were installed here which allowed them to control access to the upper Ariège valley and to keep surveillance from this strategic point over the lower land, protected behind impregnable walls.
In 1034, the castle became capital of the County of Foix and played a decisive role in medieval military history. During the two following centuries, the castle was home to Counts with shining personalities who became the soul of the Occitan resistance during the crusade against the Albigensians.