At a point where the channel leading to Waterford harbour becomes narrower, there is a rocky outcrop on the east side of the inlet, jutting out into the water. This outcrop is the location of Duncannon Fort, a strategic point in the defences of Waterford harbour. The site was fortified in ancient times and a castle was built there in the 15th century by the Normans. It guarded the entrance to Waterford harbour but also served to exert control over the local Irish people during the time when Ireland was ruled by England (and later Great Britain).
Under Queen Elizabeth I, at the time of the Spanish Armada, the decision was taken to transform the old castle into a modern artillery fort. It was two years after the Armada, in 1590, that construction actually began, but the threat of invasion was still very real. So great were the fears of attack that during the first year of the fort's construction the garrison mistook some English ships sailing into Waterford harbour for a Spanish flotilla and opened fire on them.
The fort's defences had two distinct roles; to control the entrance to Waterford harbour and to protect against a land-based assault on the fort itself. Along the sides of the fort there were guns that faced up and down the river. On the western end of the fort, which juts out into the water, there were upper and lower batteries that faced across the inlet, covering the whole river. It was these guns that could prevent any enemy ships from sailing up to Waterford.
The fort's landward defences were designed to protect the fort from an attack on its the narrow eastern side, the only side that did not face the water. This front was probably considered too short for a full bastioned trace, so instead there was an angled redan projecting from the centre of the front (see plan above). There was a deep ditch in front of the new wall, with a covered way on the other side. The fort's main entrance crossed the ditch on a bridge and entered through the right face of the redan. Behind the new wall, the old wall of the medieval castle was left in place to serve as a second line of defence.
At the foot of the landward wall on either side of the redan there were two curved brick walls with loopholes in them. These small galleries enabled the garrison to cover the ditch with musket fire. They were added at some point in the 17th century and represent an early form of caponnier. Each gallery had a sally port, a gate leading into the ditch that allowed the garrison to move into the ditch without being seen, perhaps to make a sortie or to reinforce the covered way.
To the east of the fort there is a hill known as Windmill Hill. This high ground overlooking the fort was an ideal place for an attacker to place artillery in the case of a siege. In 1606, recognising this weakness, the English increased the height of the walls on the east front of the fort. It was hoped that this would offset the disadvantage of being dominated by the hill.
During the years that followed the fort was not threatened and the fortifications were allowed to fall into some disrepair. However in 1641 the Irish rebelled against England and the fort was surrounded by hostile rebel forces. In 1645 (when the garrison had taken the side of the Parliamentarians in the English Civil War) the fort was besieged by Irish Confederates (who were allied to the Royalists in England). The port of Waterford was strategically important for the Confederates and Duncannon Fort prevented them from receiving aid from Europe by sea. The attackers placed guns on Windmill Hill, battering the walls and successfully preventing Parliamentarian ships from supplying the fort. The fort surrendered after a 2-month siege, after the garrison had repelled two assaults and were running low on ammunition.
Now in Confederate hands, the fort was attacked by Cromwell's forces in 1649 and held out successfully, contributing to the failure of the Parliamentarians to capture Waterford. However, the following year (1650) Cromwell returned to attack Waterford and Duncannon was once more under siege. The fort succeeded in holding out until Waterford fell in August and then it too surrendered to the Parliamentarians. Duncannon Fort was occupied by the British Army throughout the 19th century, as it was still a strategic site in the defence of Ireland. In the 20th century it was used for training by Irish forces, until the military left the fort in 1993.
In the years since the fort lost its military role it has been gradually restored. It is now open to the public and contains various shops, a cafe and an internet cafe. The only way to see the fortifications themselves is by a guided tour, which happen regularly throughout the day, for €5 per person. Duncannon is a rare example of an Elizabethan artillery fort. Its small size and interesting history make it an excellent place to visit and there is also a good beach next to the fort. See duncannonfort.com for more details. Duncannon is easy to access by road and can be reached by bus from nearby Waterford.