Dun Aonghasa Fort & Cliffs

Dun Aonghasa Fort & Cliffs

The Bronze Age fortress of Dun Aonghasa is one of the main attractions for people visiting Inis Mor. Perched high on the top of a 300 ft cliff on the south of the island, it is a spectacular sight with equally spectacular views to match.

Dun Aonghasa is one of the best examples of Bronze Age fortresses in Ireland, although like the equally impressive Black Fort on Inis Mor, it does have a unique aspect. This aspect, is that the defensive walls are semi-circular, basically cordoning off a part of the cliff. In one respect, it is a clever use of the natural features of the landscape that makes a completely encircling wall unnecessary. It does also make it a defense of last resort though – if the walls were ever breached from the front, the inhabitants would have nowhere to escape! This has led some people to question if its real purpose was as a fort at all, or if the complex had a more ritualistic purpose. Visitors to Dun Aonghasa can decide for themselves!

Getting to Dun Aonghasa

The fort is easily reached from the main town of Kilronan by bicycle. Daytrippers to the island can hire bicycles at the pier on arrival, and then cycle for 10 minutes up the road to reach the fort. Hiring a horse and trap is another option, as is hiking there.


The Inis Mór Seal Colony

The Inis Mor Seal Colony
Inis Mor has a seal colony which has become increasingly popular with visitors to the Aran Islands over the years. It is situated along the coastal road east of Kilmurvey beach, and is a lovely place to visit by bike. On a clear day and with the tide in your favour, you will be able to see many seals bathing. A nearby lake is home to swans, ducks, and some rare birds, making the trip here doubly worthwhile. Pro-tip – Bring some binoculars if you have them. Not only will they be useful for looking at the Seal Colony and bird watching, but they will also be useful when exploring the rest of the island.

The beaches of Inis Mór

The beaches of Inis Mor
Inis Mor does still have some wonderful beaches. Cill Mhuirbhigh is one example, and is a blue flag rated beach. During the summer months, a lifeguard is on attendance. The other Aran Islands also have good beaches. Over on Inis Oírr, there is a perfect sheltered cove near the main pier. Visitors should ask for An Trá Mhór, or if pronunciation is a problem, simply The Big Beach). Finally, Inis Meáin has several lovely little sandy coves to be discovered.

Spar Supermarket and Gourmet food


Spar supermarket is located in Kilronan Village and is where the islanders purchase their weekly food shops. It contains a wide variety of foods and has a fully stocked delicatessen, off licence, hot food’s, and food to go. Spar also has the islands only ATM machine.

Kilronan Village

Kilronan is a bustling little fishing village and hosts the port where boats to Inis Mor island dock. Most people hire bikes for the 6km trip to Dun Aonghasa. The village is the perfect place to get a coffee, use the Islands only ATM machine at the local SPA,drop you bag off where you are staying, have a swim in the turquoise water, watch the goings on in village life, people watch, and just relax in the sun. On return from Dun Aonghasa, Kilronan village is a great place for a Pint of Guinness.

Kilmurvey Craft Village

Kilmurvery craft village is located at the foot of Dun Aonghas and contains an eclectic mix of Irish Arts and crafts shops. Many visitors to the island browse through before entering Dun Aonghasa.

Dun Aonghasa Visitor Center

The very informative visitors centre should be the first stop when visiting Dun Aonghasa. There are a number of educational and informative exhibitions, artifacts, and displays which will help explain what is about to be seen at the site. The staff are also really friendly and helpful, and ready to answer questions. Anyone with mobility issues or even parents with kids in pushchairs should keep in mind that the site itself is a 900 meter walk from the visitors centre, over quite rough ground. The staff can provide advice about the walking conditions for anyone who has concerns.

Dun Aonghasa History

The Dun Aonghasa complex covers over 14 acres, with the fort itself consisting of 3 terraced walls which barricade off a sealed enclosure on the edge of a cliff. The interior of the fort can be divided into an outer, middle and inner enclosure due to the walls which start and finish at the cliff’s edge. It is thought that a small ‘safety wall’ may have lined the cliff edge itself at one time to prevent people and animals from accidentally plunging off the edge!

The fort would have been originally approached from the north, as the main entrances in the outer and middle walls face this way. Visitors today enter the fort through a breach in the outer wall, but they may notice an original doorway that is now blocked off towards the right hand side. When the fort was in use, this entrance would have been blocked by a wooden gate, and there was also a sudden drop which might have surprised people who had never been to the fort before. Excavations revealed that two young men who were possibly Vikings were buried underneath the paved entrance at around 1000 AD. It’s incredible to think that the fort was 2500 years old even then!

Who Aongus was is unknown. According to legend , Aonghas belonged to a high ranking dynasty who were displaced from their lands in Co. Meath in the early centuries AD. Another possible candidate, is Aonghus Mac Natfraich, King of Cashel in the 5th Century AD, who had dynastic affilliations with Aran.


Recent excavations by a team from the Discovery programme found evidence for human activity on the hilltop stretching over two and half thousand years (ca. 1500Bc – 1000 AD). First enclosed ca. 1100 BC , the most dynamic period in the history of this hillfort was around 800BC. At that time, Dun Aonghasa was probably the political, economic and ritual centre for a group of people with a common ancestry. Only the elite members of this group would have lived in the fort. After 700BC, the importance of the site waned and, over the the following thousand years, it seems to have been occupied only intermittantly. A major rebuilding programme was undertaken in the early Medievel period (500 – 1000 AD) but the fort was abandoned shortly afterwards. Dun Aonghasa became a National Monument at the end of the 19th century and was extensively repaired shortly afterwards. It is now conserved by the Office of Public Works.


The late Bronze Age hillfort
Covering an area of 5.7 hectares (14 acres), the interior of the hillfort is divided into an outer, middle and inner enclosure by three curvilinear walls terminating at the cliff. An additional stretch of wall runs along west side and, when the fort was occupied, there was probably a ‘safety wall’ along the cliff-edge . Outside the middle closure is a broad band of chevaux de frise (closely-set stone pillars) that even today are difficult to negotiate.

The original approach to the fort was from the north and the main entrances through the outer and middle walls face in this direction. Today, the entry point is through a breach in the outer wall, but the original doorway can be seen at some distance to the right.


Middle Enclosure
The original doorway to the middle enclosure, about 50m to the right of the present entrance, is now blocked up because of the poor condition of the roof lintals. The entrance would have been closed off by a wooden gate and the sudden drop inside the threshold was probably designed to trip any unwanted visitors. The bodies of two young men were interred in the paved entrance around 1000 AD. These may have had Viking connections, but there was no evidence to suggest that they died violently.



Inner Enclosure

Once inside the inner enclosure of Dun Aonghasa, the height of the 5 metre walls becomes all the more apparent. Over 6500 tonnes of material was used in the construction, indicating a highly organised society. A terrace on the inside would have given access to the top, and a chamber on the west side could have been some sort of arms room or store room.


Excavations within the site indicate that it was inhabited from around 1500 BC, with seven houses being built around 1100 BC. Each of these buildings had paved floors and a stone hearth. Some of the artifacts found at the site include rings, beads, tools and the remains of food, and these are now on display in the National Museum in Dublin. Due to the limited number of buildings, it is thought that only the elite class of either rulers or priests would have lived inside the walls on a permanent basis.


A rock platform near the edge of the cliff may have had some sort of ritual function, although it exact use is the subject of speculation only. Towards one side, four bronze rings which had been deliberately buried were discovered, and it is assumed that these were an offering to some deity. A large hearth at the other side of the complex was most likely used for casting bronze weapons and tools, and cooking feasts. The communal aspect of the fortress again shows a well organized society existed here.

Use through the ages

Dun Aonghasa was in use throughout the ages from the time of its construction through to around 1000 AD when the last large rebuilding work was undertaken. The burial of the two young men may be related to that last construction work. After this, the fort was then abandoned. In the 19th century it became a national monument, and today it is the premier tourist attraction on Inis Mor.