Daniel Kirkpatrick

There are few more exhilarating sites that standing on Ireland’s west coast and staring out across the seemingly endless ocean before you. The chill breeze, pungent smell of kelp, cawing of gulls, and sound of crashing waves. It’s a scene that has stood still for millennia; a frozen tableau that Ireland’s ancient forbears would have enjoyed as much as we today. And it’s the scene that greets you at one of Ireland’s most remarkable sites: Dún Aonghasa.

Dún Aonghasa is located on the Arran Islands off the West coast of Ireland near Galway on the island of Inishmore. The original hillfort was constructed around 1000BC and there’s evidence of habitation right through the Bronze Ages, Iron Age, and into the early Medieval period up to the 10^th century AD.

Mythical beginnings

Dún Aonghasa, meaning ‘Fort of Aonghas’, likely refers to King Aonghus mac Úmhór who ruled the ancient Fir Bolg peoples of Connacht. After the Fir Bolg were defeated by the invading Tuatha De Danann, legend states, King Aonghus built this fortress for his people as they settled of the coast of Connacht.¹

“The Fir Bolg fell in that battle all but a few, and they went out of Ireland in flight from the Tuatha De Danann, into Ara, and Ile, and Rachra and other islands besides….[F]rom them are named those territories…[including] the Fort of Oengus in Ara from Oengus.”²

While the myths tell us little about the actual composition or history of the hillfort, it does reinforce its significance. For the fort, like those other ancient sites of Tara, Rathcroghan or Emain Macha, was of sufficient political importance to be placed within the earliest mythological narratives of Ireland. To understand the wider context of these myths then requires turning to the archaeological evidence.

Formidable fortification

The hillfort would have required significant labour to build as “a costly signal of power of the local elite”.³ Consisting of three walled fortifications containing a mixture of domestic structures, the fort was one of the largest in Ireland. The outer, middle and inner walls form three semi-circular enclosures which terminate abruptly at the cliff-edge; a sheer 100m high drop today. Some have estimated – due to lower sea levels at the time of construction, that the cliffs may have once been an incredible 1000m high, though I personally find this unlikely for many ecological and geological reasons.

Besides its breathtaking location against the cliffs, the fort has a series of remarkable stonework defensive features. An array of stone slabs have been set in place around the middle enclosure, some as large as 2m tall. As a result, any approaching army would have been forced to break apart their shieldwall greatly undermining their defensive advance. The technical term for such a feature is a chevaux de frise, meaning Frisian horse, as such structures have historically been employed as anti-cavalry defences right up to the 19^th century (think of barbed wire barriers). To have gone to the effort of constructing such an impressive defensive feature suggests this was both a deeply contested territory and one worth protecting.

Ancient trade hub

It was strategically placed to control Atlantic maritime trade corridors, some consisting of long-distances far beyond the Irish shores as far afield as Northern Italy.⁴ Examples include “Beads made from Baltic amber” and a wide variety of exotic bronze objects.⁵ The hillfort’s location was strategically placed to “dominate seagoing traffic and serve as an economic hub for maritime exchange along the west coast”.⁶ In other words, it acted as an ancient Irish market-town. Travelling merchants would have been able to rest and recuperate at hostels and lodgings, trading their goods at local markets, before then moving on.

Notably, there were a range of moulds discovered on site alongside metalworking debris which indicate metalworking on the island itself on an industrial scale. Many of these objects were likely produced, not merely for the immediate locality, but as part of a thriving trade network with Europe. Indeed, the archaeological excavations at the site have identified an incredible array of over 2,900 artifacts.

Regional centre of power

Hillforts located on neighbouring islands show remarkable similarities but all on a much smaller scale. This has led archaeologists to suggest that Dún Aonghasa was likely a regional power centre over this network of small islands and nearby coastland.⁷ Interaction between regional chiefs would have been episodic, likely at important festivals and religious occasions. Evidence of feasting at the site indicates it had a “ritual significance”.⁸ For instance, pig bone found on site indicates it was imported (given the island hadn’t the tree coverage to support a pig population) and so was brought possibly by other elites “for communal feasting events”.⁹

Given its economic importance as a trade hub and industrial centre (at least in metalworking), alongside its strategic defensive importance at the boundaries between the Kingdoms of Connacht of Munster, it would have undoubtedly played a critical role in the politics of the wider region. Whatever chief ruled there would have profound implications on much further afield than the islands and coastland. And the remaining walls and scale of the site today only serves to reinforce this impression.

Dún Aonghasa today

Since 1880 the Irish Government has taken over the management of the site and it is now open to the public to visit. Ferries run regularly to the island and there’s a variety of accommodation available to stay on site. For more information see here.

1. DALTON, J.P., 1928. Who built Dun Aengus?. Journal of the Galway Archaeological and Historical Society, 14(1/2), pp.52-77. ↩︎
2. Extract from the Lebor Gabála Érenn: The Book of Invasions. Available at: https://www.maryjones.us/ctexts/lebor3.html ↩︎
3. Quinn, C.P., Kuijt, I., Goodale, N. and Néill, J.Ó., 2019. Along the margins? The later bronze age seascapes of Western Ireland. European Journal of Archaeology, 22(1), pp.48. ↩︎
4. O’Driscoll, J., 2017. Hillforts in prehistoric Ireland: a costly display of power?. World Archaeology, 49(4), pp.10. ↩︎
5. Quinn et al., 2019:57. ↩︎
6. Quinn et al., 2019:59. ↩︎
7. Quinn et al., 2019:60. ↩︎
8. O’Driscoll, 2019:11. ↩︎
9. O’Driscoll, 2019: 12. ↩︎