Glen Lyon is a glen in the Perth and Kinross region of Scotland. It is the longest enclosed glen in Scotland and runs for 34 miles from Loch Lyon in the west to the village of Fortingall in the east. This glen was also known as An Crom Ghleann. The land given over to the MacGregors was An Tòiseachd. It forms part of the Loch Rannoch and Glen Lyon Nationa…Glen Lyon is a glen in the Perth and Kinross region of Scotland. It is the longest enclosed glen in Scotland and runs for 34 miles from Loch Lyon in the west to the village of Fortingall in the east. This glen was also known as An Crom Ghleann. The land given over to the MacGregors was An Tòiseachd. It forms part of the Loch Rannoch and Glen Lyon National Scenic Area, one of forty such areas in Scotland, which are defined so as to identify areas of exceptional scenery and to ensure its protection from inappropriate development by restricting certain forms of development. Sir Walter Scott described Glen Lyon as the "longest, loneliest and loveliest glen in Scotland". Apart from a few scattered farms and cottages throughout the glen, the only real settlements are at Fortingall and Bridge of Balgie.