Dún Aonghasa
About 1 km each way from the visitor centre · Rising, rough natural rock underfoot; no formal steps elevation
About
Dún Aonghasa is the reason most people come to Inis Mór: a dry-stone fort of three concentric ramparts perched on a limestone cliff above Cill Mhuirbhigh (Kilmurvy) that drops roughly 100 metres straight into the Atlantic, with a band of jagged upright defensive stones, a chevaux-de-frise, ringing the outer wall. Excavations date the first enclosure to around 1100 BC, with Bronze Age activity around 900 BC and the triple-wall defences likely added around 500 BC; the site was refortified again around AD 700-800. The OPW visitor centre has an exhibition and runs the ticketing; from there it is about a 1 km walk up rising, rough natural rock to the fort itself, roughly 1 to 1.5 hours round trip. There is no fence or barrier at the cliff edge, so care is genuinely needed, especially with children or in wind.
Photos
Highlights
- ✓Three concentric dry-stone ramparts over 3,000 years old
- ✓A chevaux-de-frise, a defensive band of jagged upright stones
- ✓A sheer, unfenced 100-metre drop into the Atlantic
- ✓OPW visitor centre with exhibition and guided information
Tips
- →Wear proper walking shoes; the path is rough, rising natural rock, not a paved trail.
- →There is no barrier at the cliff edge; keep well back, especially in wind or with children.
- →Arrive on an early ferry and head straight out to beat the midday crowds in July and August.
- →Free entry for overnight guests of participating island accommodation; ask when you book.
- →Admission is free to individual visitors and families on the first Wednesday of each month under the OPW Free Wednesday scheme (not organised group tours or commercial tour operators; heritageireland.ie, checked 2026-10-14).
