Inland of Hurghada the barren plains erupt into the Red Sea Mountains , which follow the coast southwards towards Ethiopia. This geologically primitive range of granite, porphyry and breccia contains Egypt's highest mountains outside Sinai, rearing up to 2187m (over 7000ft) above sea level. During winter, peaks exceeding 1500m draw moisture from rising masses of air, while in summertime they precipitate brief, localized storms accompanied by violent lightning and flash floods. Hardy desert plants flourish in their wake, providing grazing for feral ruminants and the flocks of a few thousand nomads. Roaming their vast tribal lands, these Bedouin are perfectly at home in the wilderness - unlike isolated groups of miners and soldiers, who feel almost as exiled as the slaves who quarried here in ancient times.