"He didn’t want level surfaces or follow-the-leader crowds. True adventure was to be alone. The terrain he traversed was steep slippy grass, or sheer clumps of rock where you had to climb or jump. Sometimes only shepherds or sheep had been that way before. Often you found your way just by eye and compass. If you were lucky, there was a good bright day, and close-burned heather to run on. If you were unlucky there was thick mist, loose scree, and a headlong descent down through rocks and bracken where you had to leap as much as run, risking a broken leg."
From The Economist's obituary of British fell runner Bill Smith, who died doing what he loved best (http://www.economist.com/node/21533348)