Dun Aonghasa

Perched spectacularly on a cliff overlooking the Atlantic ocean, this is the largest of the prehistoric stone forts of the Aran Islands. It is enclosed by three massive dry-stone walls and a "chevaux-de-frise" consisting of tall blocks of limestone set vertically into the ground to deter attackers.
The fort is about 900m from the Visitor Centre and is approached over rising ground and visitors are advised to wear weather protective clothing and shoes suitable for walking over uneven terrain.