Sandwiched between the lochs of Nevis and Hourn (Gaelic for “heaven” and “hell,” respectively), Knoydart is a kind of geographic purgatory. This remote one-road knuckle of land on Scotland’s northwest coast, long known as the Rough Bounds, is defined by its savagely wild terrain. Accessible only by sea ferry or by a punishing multiday hike of no fewer than 16 miles, it sounds like a place of banis...