Twi Ness rather than meaning twin-ness is said to be tongue-ness as there is no double headland, but the name Point of Dishan can only go as far back as The Douche so could well have been the other half of a Twi Ness (Doocot Point is shown seperately). The mound sits above the rocky headland. I wonder if the large stones in the cliff face part of a stoney outcrop on which the mound is placed or placed stone ? Because the upright slab being radial sounds like it might be more a divider than an encloser – wheelhouse maybe