Described in Low’s _Tour in Orkney and Shetland_, 1774 (Kirkwall, 1879), p. 177; and by Dr. Arthur Mitchell in the _Proceedings of the Society of Antiquaries of Scotland_, vol. xv. p. 304.
Such instances of the adaptation of natural islands in lochs as places of strength by constructing defensive buildings of stone upon them are not uncommon, although it rarely happens that the form and characteristics of the buildings themselves are so clearly traceable. But there is another variety of defensive construction which is more frequently found in similar positions. It possesses the additional peculiarity of being either wholly or partially constructed of wood.
The Lake-Dwellings in Scotland, which are either wholly or partially constructed of wood, and which on that account are known as Crannogs, are very numerous, but so few of them have yet been systematically explored that it is impossible to determine with any degree of certainty the special characteristics of their typical form and structural arrangements. Indeed, it is questionable whether this knowledge may be in any measure attainable by investigation of their existing remains. Constructed of perishable material, which, as long as it survived the ravages of time, was capable of being adapted to many and various purposes of general utility, the parts of the Crannogs that stood above the water were almost certain to be gradually destroyed. But whatever may have been the special form of the superstructure of the Lake-Dwelling when it was built of timber instead of stone, the typical Crannog, taken as a whole, differs from the stone-built strengths that are placed in lakes not only in the substitution of timber in place of stone as the material of its construction, but also in being constructed usually on an island that is itself an artificial construction. The Crannog is therefore a Lake-Dwelling, actually built up from the lake-bottom. Of the structure which stood above the water, and gave shelter and habitable houseroom to the inmates, there is usually no trace whatever. Occasionally the remains of a pavement of timber or of flagstones, or the site of a hearth with its accumulations of ashes and food refuse marks the level of the floor, and sometimes a succession of such indications at different levels may betoken successive occupations. But the story of the Crannog as told by the casual relics imbedded in and around its submerged foundations is clearly intelligible, although it reveals nothing of the precise form and arrangements of the habitable part of the structure.