19 July 2019
Visiting Dún Aonghasa,
the clifftop hill fort at
the edge of the Atlantic
Inishmore is the largest of the Aran Islands in Galway Bay, and is called Árainn by the islanders themselves. In the past it has also been known as Arran, but the ferry companies and tourist guides all call it Inishmore, which helps to distinguish it from the other Aran Islands – Inishmaan and Inisheer – and from Arranmore off the coast of Donegal and the Isle of Arran in Scotland.
People have been living on Inishmore, the largest of the Aran Islands, for perhaps 5,000 years, and Inishmore has one of the highest concentrations of National Monuments in Ireland.
By the year 1100 BC, people on the island had built Dún Aonghasa (Dun Aengus), the best-known of the prehistoric hill forts on the Aran Islands, at the edge of a 100 metre high (330 ft) cliff on the south side of the island. It is one of the best examples of its kind in Europe, and is the most important archaeological site on the island.
This is also one of Ireland’s most visited sites, attracting archaeologists, scholars and tourists from all over the world.
Dún Aonghasa is a Bronze Age hill fort overlooking the Atlantic, with daunting, dramatic views that stretch the length of the Island. The site covers 5.7 hectare (14 acre), and the fort consists of three terraced walls surrounding an inner enclosure containing a platform on the edge of the 100 metre cliff top.
Archaeological excavations have found evidence of people living on the hilltop for over 2,500 years from ca 1500 BC to 1000 AD. It was built at a strategic location, at the narrowest point on the island, at the highest point on the cliffs, and close to a sheltered harbour, in a position to dominate the island and the surrounding sea.
The first walls and dwelling houses were built here ca 1100 BC. Building was a major undertaking for the island’s inhabitants at the time. Archaeologists estimate the building project would have involved a team of 30 builders working seasonally and taking 12 years to complete their work.
The whole structure is surrounded by a network of defensive stones known as a chevaux de fries, dating from ca 700 BC.
The most dynamic period in the history of this hillfort was around 800 BC. At that time, Dún 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. Some scholars suggest the platform overlooking the Atlantic had a ritual function.
The importance of the site waned after 700 BC and, over the following 1,000 years, it seems to have been occupied only intermittently. Although a major rebuilding programme was undertaken in the early mediaeval period (500-1000 AD), the fort was abandoned soon after.
Inside, the hillfort is divided into an outer, middle and inner enclosure by three curvilinear walls that end at the cliff. An additional stretch of wall runs along the west side. When the fort was occupied, there may have been a ‘safety wall’ along the cliff-edge.
Outside the middle closure is a broad band of chevaux de fries or closely-set stone pillars that are difficult to negotiate, even today.
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 is some distance away to the right.
The original doorway to the middle enclosure, about 50 metres to the right of the present entrance, is now blocked up because of the poor condition of the roof lintels. The entrance would have been closed off by a wooden gate and the sudden drop inside the threshold was probably designed to trip any intruders. The bodies of two young men were buried in the paved entrance around 1000 AD. They may have had Viking connections, but there is no evidence that they died violently.
The inner enclosing wall is 5 metres wide. It was built up in layers so that the foundations could be stepped over rising ground. Originally, it was about 6 metres high and about 6,500 tonnes of stone were used to build it. The terrace inside gave access to the top of the wall and a small chamber in the west side of the wall may have been used to store precious or perishable goods.
The stone foundations of seven houses were found in the inner enclosure. The floors were paved and some of the houses had a stone hearth. The outline of a circular house, about 5 metres in diameter, is still visible near the west wall. Its foundations are partly covered by the enclosing wall, indicating the house predates the final alterations to the defences.
A stone trough outside the door may have been used for storing water, keeping shellfish fresh, or for boiling meat on a hot stone. Meat, cereals, fish and shellfish were part of the diet of the late bronze Age occupants. Almost 8 tonnes of limpet shells were found during the excavations.
Most of the tools in everyday use – hammers, axes, whetstones, and quern stones – were made of stone. Clothing was made from wool or leather and fastened with bone pins.
The rock platform at the edge may have had a ritual or ceremonial function. A hoard of four bronze rings deliberately buried beside it was probably an offering to a deity.
At the opposite end of the inner enclosure, a large hearth seems to have been associated with communal feasting and with the casting of bronze weapons and tools.
Late Bronze Age objects, including rings, tools, beads and foodstuffs, have been found on site and are now in the National Museum of Ireland, Dublin.
Dún Aonghasa became a National Monument at the end of the 19th century and was extensively repaired shortly afterwards. It was one of the first archaeological sites taken into state care in Ireland, and is now managed by the Office of Public Works.
But who was Aonghas? 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 fifth century AD, who had dynastic links with Aran.
The Dún Aonghasa Visitor Centre is on the edge of Kilmurvey Craft Village, at the foot of Dún Aonghasa. From there, it is a 1 km walk to the site, along a rough gravel path.
When we climbed back down along the rough path, we stopped in Kilmurvey for coffee in the summer sunshine before returning to Kilronan, the island’s main village and port, where we had lunch as we waited for the ferry to take us back to Doolin.