Dunseverick Castle

Dunseverick Castle

Perched on the Causeway coastline, Dunseverick Castle is an ancient royal site of the Dál Riada, a Gaelic kingdom from at least the 5th century AD. Located near the small County Antrim village of Dunseverick, this impressive coastal promontory fort was said to have been blessed by Saint Patrick.

Located on the Causeway Cliff Path, Dunseverick Castle and peninsula on which it stands, were given to the National Trust in 1962 by a local farmer, Jack McCurdy. Recorded in the Irish Annals as Dun Sobhairce, Dunseverick Castle and its earthworks are now Scheduled Historic Monuments. 

History of Dunseverick Castle

The annals record that Dunseverick Fort was attacked by the Vikings in 871 and 924 AD. It became a manorial centre of the Earls of Ulster from around 1250 to 1350 AD and then a stronghold of the O’Cahans and later the McDonnells from 1560 AD.

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 northern area of the site contains an oval depression of wet ground which is thought to be a holy well. It has unsurprisingly become known as Saint Patrick’s Well.

In the later part of the 6th century AD, Dunseverick Castle was the seat of Fergus Mor MacErc (Fergus the Great). Fergus was King of Dál Riada and brother of the High King of Ireland, Murtagh MacErc.

The castle was captured and destroyed by Cromwellian troops in the 1650s. However, it was recorded as being destroyed by a Scottish army under the command of General Robert Munro who was sent with his troops to Ireland in 1642.

Today only the ruins of the gate lodge remain. A small residential tower survived until 1978 when it eventually surrendered to the sea below.

Dunseverick - an archaeology angle

Although Dunseverick Fort has not been excavated, it is still possible to interpret some of the remains which survive on and around the basalt stack. The approach to the fort, from the southwest, is protected by a prominent 3.7m wide bank with an external ditch 3.9m wide. Further ditches are visible towards the south. With its steep sides, the basalt stack on which the fort sits affords considerable natural protection although a very low bank surrounds much of the summit.

The top of the promontory is relatively flat and measures 121m in length by 43m at its maximum width. The interior is sub-divided by number of low earthwork banks and by a prominent ditch, 2.8m wide which seems to cut-off or partition the far northern end of the summit. The northern area contains the sight known as a Saint Patrick’s Well.

The central part of the summit contains the remains of a large rectangular enclosure composed of earthwork banks. To the southeast of this enclosure lies a structure divided into two rooms and measuring 15m by 8m externally, with an entrance gap at the southwest. Another structure lies southwest of this and is a single room in plan, measuring 12m by 8.7m externally, with a doorway in the middle of the northeast side. At the narrow southeast tail of the rock lies a ruined two-storey masonry tower. It measures 5.8m by 6.7m externally and is constructed of polygonal volcanic basalt stones and mortar with a north facing entrance 1.2m wide.

To date the only archaeological investigations at the site have taken place within a cave located at the south end of the western inlet. In 2007 and 2008, the Centre for Maritime Archaeology (University of Ulster) and Centre for Archaeological Fieldwork (Queens University Belfast) excavated several trenches within the cave. The cave itself is 16m wide with a maximum depth of c.5.5m and is at most 2.85m in height. The only artificial feature found was a short section of rubble-built wall possibly bonded in clay located near the mouth of the cave on the western side and the excavation revealed this to be medieval in date.

Excavation in progress within Dunseverick Cave in 2007
Excavation in progress within Dunseverick Cave in 2007
Excavation in progress within Dunseverick Cave in 2007

Within the cave itself, archaeological deposits were found containing small amounts of pottery of Early Medieval, Medieval and post Medieval date, though the excavations remain to be completed and interestingly it ceased at a very interesting stage when a deposit of possibly 12th or 13th date was encountered containing animal bone and pottery. This deposit is therefore probably contemporary with the Anglo-Norman occupation of the Fort.  Evidence also emerged during excavation that either in the medieval or early in the Post Medieval period the cave was used for an unidentified industrial process involving a large fire. One theory is that this may have been linked to the firing of locally made pottery.

Recently the Department of Archaeology at Queens University Belfast and at University of Aberdeen have begun research at Dunseverick Castle as part of a Leverhulme funded project focusing on the early medieval kingdoms of Scotland and Ireland. The team of archaeologists have been examining recent LiDAR imagery of the site and have also carried out geophysical surveys (Electrical Resistance, Gradiometry & Electromagnetic Conductivity).

Extract from LiDAR survey results of Dunseverick Fort presented as a DEM showing prominence of the earthwork features on and below summit.
Dunseverick Castle LiDAR results
Extract from LiDAR survey results of Dunseverick Fort presented as a DEM showing prominence of the earthwork features on and below summit.