Not as easily accessible as Dun Aonghasa but worth making the extra effort for you will need to head towards Cill Einne/Killeany from Cill Ronain/Kilronan about one mile as far as the disused electricity station on the right hand side. It is a grey building tucked in under a cliff with a small salt lake beside it. Take the turn to the right here. At the top of the hill turn right again and follow the road out to the cliffs. As the road begins to rise, cast your eye to the right to the rock face on the far side. If you are visiting during Spring or early Summer, you will spot a large number of herons　nesting in the bushes and on the cliff face. Heron’s nest as a colony and this area is the island’s heronry.
The road deteriorates towards the cliffs and eventually disappears altogether. When at the cliff face, take a left and Dun Dubhchathair will be before you.
It has a different “feel” to it than Dun Aonghasa, not quite as spectacular- but some people prefer it. The fort itself is situated on a stone promontory that stretches out to the sea, to the cliffs to the South. Outside there is single line of walls that reaches up to 6 meters in height and 5 meters in depth. To the inside of the walls, in the central area, there are some ruins of those that should have been rooms with unknown functions constructed in medieval age.