The most significant battle fought on West Ardnamurchan was in 1519, a battle which was a disaster for the MacIains, with their chief, John, and two of his sons being killed. The Diary, keen to locate the battlefield, has done some research on the internet for clues to its exact location.
According to the Royal Commission on the Ancient and Historic Monuments of Scotland, 'the battle was fought on the low-lying land at the base of Craig an Airgid (NM 47 66) 3 miles from Kilchoan, between the MacIans of Ardnamurchan and the Macdonalds of Lochalsh, assisted by the MacLeods of Lewis, MacLeods of Raasay, and Macdonalds of Dunnyveg, the former being heavily defeated. Though unable to find them, M E M Donaldson (1930) states that cairns commemorating the battle lie somewhere in a hollow between two lines of hills on the right hand side of the road (travelling from Kilchoan) beyond the second bridge before Craig an Airgid is reached.'
A map, here, shows the grid square NM4766, and a marker - which isn't helpful as it is simply at the point where easting 47 crosses northing 66 - but this square does include the 'low-lying land at the base of Creag an Airgid', near the rock on which stones are placed to bring good luck (Diary posting here).
Other sources, including 'The Annals of the Parish', state that the chief's cairn is 'near the old march dyke between Kilchoan and Glendrian farm'. The Diary is uncertain of the meaning of 'march', and dyke can be a ditch or a wall, but takes it as the boundary between the two farms. Today, very roughly, this is followed by the Ardnamurchan Estate fence, which is shown on the 1:25,000 OS map.
Donald MacDiarmid, in his 'Ardnamurchan Place Names', says that the site of the cairn 'can yet be identified on a knoll close under the south-west side of Creag an Airgid', and that the followers' grave is 'at a place which can also be pointed out'.
Armed with this information, The Diary and wife set out to find the cairn.
Both the pictures on this posting show knolls to the southwest of Creag an Airgid and on the right hand side of the road. The top one shows the most obvious knoll, with Creag an Airgid rising directly behind it. The second knoll is rather more to the south of the hill.
Both knolls were thoroughly searched, as were the valleys between them, but nothing was found that might be a cairn.
A map of the area is here.