Dún Aonghasa

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Perilously perched on a sheer sea-cliff, Dún Aonghasa defiantly faces the Atlantic Ocean. It is the largest of the prehistoric stone forts of the Aran Islands.

Perilously perched on a sheer 100-metre sea-cliff, Dún Aonghasa is one of western Europe's most magnificent stone forts and the largest of the prehistoric forts on the Aran Islands. The fort consists of three massive drystone defence walls built in concentric circles. Outside them is a chevaux-de-frise - a dense band of jagged, upright stones, thousands in number, creating a devastatingly effective way to impede intruders. This remarkable defensive system surrounds the entire fort from cliff to cliff. The fort is approached over rising ground and rough, natural rock, with the final approach offering spectacular views across the karst landscape of Inis Mór. At the cliff edge, there is no fence or barrier at the 87-metre drop, adding to the dramatic and somewhat perilous atmosphere of this ancient site.

History: Dún Aonghasa is over 3,000 years old, with construction dating back to approximately 1100 BC when rubble was first piled against large upright stones to form the initial enclosure. Excavations have revealed significant evidence of prehistoric metalworking, including bronze casting moulds dated to around 900 BC, as well as several houses and burials. Around 500 BC, the triple wall defenses were constructed along the fort's western side. The whole complex was refortified in AD 700-800 during the early Medieval period. An early Iron Age bird-head fibula (brooch) was discovered in a wall of the site in 1839. The fort's name, meaning 'Fort of Aonghas', may refer to the pre-Christian god Aengus described in Irish mythology, or the mythical king Aonghus mac Úmhór. It has traditionally been associated with the Fir Bolg, a legendary people in Irish mythology. At the time of construction, sea levels were considerably lower and the fort was originally approximately 1000 metres from the sea, though parts of the cliff and fort have since collapsed into the Atlantic.

Significance: Dún Aonghasa is recognized as one of the finest examples of prehistoric military architecture in Western Europe. The outermost wall encloses approximately 6 hectares (14 acres), making it impressively large among prehistoric ruins. It represents an extraordinary achievement of Bronze Age and Iron Age construction, with its massive drystone walls, sophisticated defensive chevaux-de-frise system, and dramatic clifftop setting. The site is a National Monument of Ireland and one of the country's most popular and iconic archaeological attractions, drawing visitors from around the world to experience its ancient power and breathtaking location on the edge of the Atlantic.

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