Another archaeologicl ambulation

I am lucky enough to have a local friend who has a boat and enjoys taking it out to explore the more remote countryside of Uist. Today we went to the rugged area at the SW end of Eaval, the highest hill on North Uist. Plenty of archaeology already recorded there but, as we found, plenty unrecorded too.
This particular one has been well documented, not surprisingly, as behind me as I took the photo is a circular wall three metres thick and about twenty metres in diameter - Dun-an-Siamain. Duns are enigmatic structures scattered over the Hebrides and normally consist of two circular walls that support each other to a height of up to 12m. Impressive structures.
The image shows the causeway out to this island fort and the ever-present Eaval. Siamain means "a rope made of twisted heather" so presumably that as involved in the construction somewhere.....
Otherwise lots of shielings and graves along with a variety of inexplicable - for us at least - structures. Another eight hour day out and about made the house seem welcome on our return.