There doesn't seem to be much if anything left of the stones of the dun wall here at Balephuil, according to Canmore. But it was built in a very well protected spot, on a corner of a rocky stack sticking out into the sea.
I like this story a lot.
One night toward the close of the eighteenth century, when a certain Dugald Campbell was tending the cows belonging to the farm of Baile-phuil, on the coast of Tiree, a small, red cow came among the herd. The Baile-phuil cows immediately proceeded to set about it with their horns. When it fled, they followed it. Dugald joined in the pursuit, during which, as he himself testified, the little, red cow at one moment seemed to be quite near him, and at another moment very far off. The chase was brought to an abrupt end when the little, red cow entered the face of a rock, and thus disappeared from view, never to be seen again by human eye.
In relating this incident, Dugald Campbell insisted that he had the greatest difficulty in preventing the Baile-phuil cows from following the intruder into the face of the rock.
From The peat-fire flame by Alasdair Alpin MacGregor (1937). The cow of course is a red fairy cow, one of the cro sith which you might find on Tiree.