Climb to a prehistoric fort that stops at an unfenced cliff

Dún Aonghasa is a stone fort more than three thousand years old, on the edge of Inis Mór, the largest of the Aran Islands. It is three massive drystone walls, one inside another, and the innermost ends at the cliff: an 87-meter drop to the sea, with no fence and no railing.

The island is a boat ride out. From the harbor it is seven kilometers west between stone walls, by bike or the island minibus, and then about a kilometer on foot over rising ground. The last stretch is bare natural rock, which is the case for proper shoes.

Outside the walls, thousands of jagged stones stand upright in a band around the fort from cliff to cliff. Inside is the edge, and how close anybody stands to it is left entirely to them.