What new madness is this? A Scottish site I'd actually heard of before donning the boots this time around! OK, that's not strictly true since it appears the hill fort is referred to locally as 'Knock Farril'.... but I'm assuming it's probably pronounced more or less the same. Correct me if I'm wrong. Regardless of nomenclature, it's certainly a good 'un requiring precious little introduction - thankfully - to the hardened Scottish 'hill Head', not only due to the fine location, straddling a narrow NE-SW ridge approx midway between the spa-town of Strathpeffer and Dingwall (the latter upon the shore of Cromarty Firth looking across to those curiously alien oil platforms), but because of the extensive vitrification of the defences. Ah, 'vitrification', that seemingly almost mystical process whereby dry stone walls of hill forts, most particularly in Scotland, were subjected to severe, uniform heat - aka fire - causing the stone to fuse to a hard glass-like substance. Or something like that. The reasoning behind such acts has, not surprisingly, been the subject of much academic debate... for what it's worth I favour the 'ritualistic decommissioning' option at time of typing. So that's that settled, then.
The hill fort towers impressively above the aforementioned Strathpeffer, which incidentally possesses a Pictish Clach Tiompan, or 'sounding stone'. Needless to say, however, I approach from Loch Ussie to the south, a rough track actually allowing visitors to park upon the ridge to SW, if they so wish. In my ignorance I leave the car a little further down beside the farm house and make my way on foot... in retrospect it is more appropriate, I think. The ascent to the 'fort is quite steep, passing a vitrified outwork described by Canmore as a 'look-out post'; there is another to the NE of the main enclosure, so my interpretation is they might have also functioned as 'barbicans' protecting the main approaches from sudden assault? There is certainly quite a substantial volume of vitrified rock remaining in situ from what must have been a very powerful univallate defence in its day (Canmore gives an average of c4.5m for wall thickness).
Interestingly.... Anna and Graham Ritchie (Oxford Archaeological Guide to Scotland) cite Knock Farril as being the location of the earliest recorded excavation in Scotland during 1774, the dig resulting in the trio of 'distinct troughs' to be seen. More interesting still, perhaps, they also state that analysis of the vitrified rock yielded a destruction date of c1,100 BCE. Blimey, that is early, is it not? As I wander around taking in the fabulous views, special mention accorded the vistas looking eastward toward Cromarty Firth and north to Ben Wyvis, Auld Alba decides to add a primeval vibe by introducing fast moving fronts of violent hail, tempered by exquisitely sublime rainbows. Just to make the visit to this wondrous hill fort even more memorable, you understand, and not to give me a randomly generated kicking. Thank you Mam.
Incidentally I learn later that my nephew's little girl, Evelyn, upon seeing a rainbow at home in South Wales asked the Mam C whether she could 'go for a ride on it', or words to that effect. You know, up here on Knock Farril, I think I know what she meant. Never lose the child inside, my friends. Never!
There is a tradition of this part of the country which seems not a great deal more modern than the urns or their ornaments, and which bears the character of the savage nearly as distinctly impressed on it. On the summit of Knock-Ferril, a steep hill which rises a few miles to the west of Dingwall, there are the remains of one of those vitrified forts which so puzzle and interest the antiquary; and which was originally constructed, says tradition, by a gigantic tribe of Fions, for the protection of their wives and children, when they themselves were engaged in hunting.
It chanced in one of their excursions that a mean-spirited little fellow of the party, not much more than fifteen feet in height, was so distanced by his more active brethren, that, leaving them to follow out the chase, he returned home, and throwing himself down, much fatigued, on the side of the eminence, fell fast asleep. Garry, for so the unlucky hunter was called, was no favourite with the women of the tribe; - he was spiritless and diminutive, and ill tempered; and as they could make little else of him that they cared for, they converted him into the butt of all their severer joke, and less agreeable humours. On seeing that he had fallen asleep they stole out to where he lay, and after fastening his long hair with pegs to the grass, awakened him with their shouts and their laughter. He strove to extricate himself, but in vain; until at length infuriated by their gibes, and the pain of his own exertions, he wrenched up his head, leaving half his locks behind him, and hurrying after them, set fire to the stronghold into which they had rushed for shelter. The flames rose till they mounted over the roof, and broke out at every slit and opening; but Garry, unmoved by the shrieks and groans of the sufferers within, held fast the door until all was silent; when he fled into the remote Highlands, towards the west.
The males of the tribe, who had, meanwhile, been engaged in hunting on that part of the northern Sutor which bears the name of the hill of Nig, -- alarmed by the vast column of smoke which they saw ascending from their dwelling, came pressing to the frith of Cromarty, and leaping across on their hunting spears, they hurried home. But they arrived to find only a huge pile of embers in which the very stones of the building were sputtering and bubbling with the intense heat like the contents of a boiling caldron. Wild with rage and astonishment, and yet collected enough to conclude that none but Garry could be the author of a deed so barbarous, they tracked him into a nameless Highland glen, which has ever since been known as Glen-Garry, and there tore him to pieces. And as all the women of the tribe had perished in the flames, there was an end, when this forlorn and widowed generation had passed away, to the whole race of the Fions.
On the summit of the hill we met two boys herding cows [...and] we were curious enough to ask them if they ever heard of Coinneach Odhar [the Brahan Seer] in the district, and if he ever said anything regarding the fort on Knockfarrel. They took us to what they called "Fingal's Well," in the interior of the ruined fort, and said that this well was used by the inhabitants of the fortress "until Fingal, one day, drove them out, and placed a large stone over the well, which has ever since kept the water from oozing up, after which he jumped to the other side of the (Strathpeffer) valley."
There being considerable rains for some days prior to our visit, water could be seen in the "well," but one of the boys drove down his stick until he reached the stone, producing a hollow sound which unmistakably indicated the existence of a cavity beneath it. "Coinneach Odhar foretold," said the boy, "that if ever that stone was taken out of its place, Loch Ussie would ooze up through the well and flood the valley below to such an extent that ships would sail up to Strathpeffer and be fastened to Clach an Tiompan; and this would happen after the stone had fallen three times. It has already fallen twice, " continued our youthful informant, "and you can now see it newly raised, strongly and carefully propped up, near the end of the doctor's house."
From 'The Prophecies of the Brahan Seer' by Alexander Mackenzie (1877).
The vitrified fort on Knock-Farril, in Ross-shire, is said to have been one of Fin McCoul's castles; and Knock-Farril, or rather "a knoll opposite Knock-Farril" is remembered as the abode of the Fairies of that district.
 Proceedings of Society of Antiquaries of Scotland, vol. vii. p. 294, note.
 See, for example, an article on "Scottish Customs and Folk lore," in The Glasgow Herald of August 1, 1891
From 'Fians, Fairies and Picts', by David MacRitchie, 1893.