Dún Aonghasa is one of the largest prehistoric stone forts in Europe and stands guard over Inis Mór on the edge of a 100-metre sheer cliff drop.
Sometimes anglicised as Dun Aengus, the fort was built around 1100 BC and is protected by remarkable chevaux de frise, fearsome, defensive limestone spikes. The entirety of the site is about 14 acres and the displays at the small visitor center provide additional context.
As powerful swells pound the cliff face below, on top you’ll get some of the finest and most jaw-dropping views you'll find anywhere in the Aran Islands. To preserve the site, there are no railings or any other modern additions so you can go right up to the cliff's edge, but also potentially fall to your doom below – take extra care as gusts of wind can catch you unaware.
Tickets and other practicalities
Access to the ring fort is through the visitor center for the fee of €5 with concessions available. From there it’s a short uphill hike to the peak of the fort.