Ben Nevis, the highest mountain in the United Kingdom, is in the S.W. corner of Inverness-shire, between Loch Eil and Loch Leven, and 7 miles distant from Fort William. It has an elevation of 4,406 feet, and the circumference of the base measures 24 miles. To the N. and N.E. its flanks are, very precipitous with a sheer height of 1,500 feet. Geologically the structure may be described as granite and gneiss capped with porphyry. Since 1883 the Scottish Meteorological Society has had an observatory on the summit.