TREISHNISH, isles, in the parish of Kilninian, county of Inverness. These are a cluster of small islands, lying about four leagues westward of the Isle of Mull, and in the vicinity of Staffa. One of them, designated Cairn-burgh-more, was formerly considered by the natives as a place of great strength, and its castle was generally occupied by a small party; it is a high rock, of considerable extent, and inaccessible on all sides except by one narrow pass. Another, Cairn-burghbeg, is a smaller rock near it, separated by a narrow sound, and to which the same description in every respect applies. These rocks are said to have been the boundary of the two governments into which the Hebrides were divided when subject to the crown of Denmark. In 1249, Cairn-burgh-more was summoned to surrender to Alexander III., who meditated the conquest of the Hebridean islands. The Macleans possessed it in 1715, and during the rebellion of that year it was taken and retaken by each of the contending parties.