The remains of the fort at Creag Garten are on an isolated rocky knoll in the forest, and have "extensive views to the North and South" according to the record via Pastmap. It seems in the right area to relate to the following story, collected in Strathspey.
About a hundred years ago, a farm labourer was walking through the woods at Garten Beg towards Carrbridge, on a very misty evening, when he heard the strains of the most wonderful music he had ever heard in his life. Walking towards the sounds, he could see nothing, and the music became fainter and fainter, gradually dying away entirely.
On reaching his home, he informed his old mother, who promptly said: "Oh, those were the fairies blowing their fog horn, while on the march from one place of abode to another."
This is reputed to be perfectly true, and the music had been heard on many occasions. The wood is very rocky and abounds in huge boulders, and to this day a cave is pointed out as one of the resting places of those self same fairy folk.
(Told to Murdoch Maclennan of Dulnain Bridge, Speyside, Scotland, by the farm labourer's grandson.)
E. J. Begg
Folklore, Vol. 50, No. 1. (Mar., 1939), pp. 75-81.