A Journey to the Western Islands appeared in 1775, and recounted Johnson's and Boswell's tour through the Hebrides in autumn 1773. (Boswell's own account of the journey, Journal of a Tour of the Hebrides, appeared in 1785; the two are profitably read together, although they're very different.)
Boswell proposed the trip to the northwest of Scotland, although it was often postponed. Together they visited Edinburgh, St. Andrews, Aberdeen, Inverness, Skye, Raasay, Coll, Mull, and Glasgow. The book's publication aroused much Scottish resentment, not least from James Macpherson, whose Poems of Ossian Johnson attacked as fraudulent in the Journey.
You can save money with Johnson's Journey to the Western Islands of Scotland and Boswell's Journal of a Tour to the Hebrides with Samuel Johnson, LL.D., ed. R. W Chapman (Oxford: Oxford Univ. Press, 1924), often reprinted in paperback in the Standard Authors series. There's no commentary.
This is part of a Guide to Samuel Johnson by Jack Lynch. Comments are welcome.