The four-hundred-and-fifty-mile long Draa River Valley in the Moroccan Sahara contains some of the most sumptuous oases and searing desert of the Arab world, starting in the moonscape gorges of the Anti Atlas Mountains through to a green sea of date palms over which rise the many-towered casbahs of ochre coloured clay, medieval in aspect and sheltering a life medieval in character. It is a region richer historically and ethnically than anywhere else in North Africa. The river stretches to the mosaic of dunes and parched land known as hammada - the domain of Bedouin and Blue Men and isolated Berber tribes - and pours through the desert into the Atlantic, where it ends its course. Jeffrey Tayler follows the Draa by foot and on camel, recounting stays in casbah homes, weddings, visits to mosques and marabouts and nights in hashish dens. It is a journey marked with extremes - of weather, as Tayler survives intense heat and sandstorms and potentially lethal local tribesmen - and one which he only narrowly escapes to tell this tale.