been traditionally divided into five districts: Mar, mostly between the Dee and Don, which nearly covers the southern half of the county and contains the city of Aberdeen. It is mountainous, especially Braemar, which contains the greatest mass of elevated land in the British Isles. The Dee valley has sandy soil, the Don valley loamy. Formartine, between the lower Don and Ythan, has a sandy coast, which is succeeded inland by a clayey, fertile, tilled tract, and then by low hills, moors, mosses and tilled land. Buchan lies north of the Ythan, and comprising the north-east of the county, is next in size to Mar, parts of the coast being bold and rocky, the interior bare, low, flat, undulating and in places peaty. On the coast, six miles (10 km) south of Peterhead, are the Bullers of Buchan – a basin in which the sea, entering by a natural arch, boils up violently in stormy weather. Buchan Ness is the most easterly point of Scotland. Garioch, in the centre of the shire, comprises an undulating, loamy, fertile valley, formerly called the granary of Aberdeen. Strathbogie, occupying a considerable area south of the Deveron, mostly consists of hills, moors and mosses. The interior mountains of the Cairngorms provide the most striking of the physical features of the county: Ben Macdhui, , a magnificent mass, the second highest mountain in the United Kingdom (shared with Banffshire) Braeriach Cairn Toul, Beinn a' Bhùird, Ben Avon, "Dark" Lochnagar, Cairn Eas, , Sgarsoch, Culardoch Farther north rise the Buck of Cabrach, on the Banffshire border, Tap o' Noth, , Bennachie, , which from its central position is a landmark visible from many different parts of the county, and which is celebrated in John Imlah's song, O gin I war faur the Gadie rins, and Foudland, . The chief rivers are the Dee, long; the Don, ; the Ythan, , with mussel-beds at its mouth; the Ugie, , and the Deveron, , partly on the boundary of Banffshire. In 1911 the rivers abounded with salmon and trout, and the pearl mussel occurs in the Ythan and Don. A valuable pearl in the Scottish crown is said to be from the Ythan. Loch Muick, the largest of the few lakes in the county, above the sea, long and broad, lies some southwest of Ballater, and has Altnagiuthasach, a royal shooting-box, near its south-western end. Loch Strathbeg, southeast