National Geographic : 1973 Aug
Fickle sculptor, the wind each day reshapes Sahara dunes. These f50-foot-high waves flow across the Erg Bourarhet region. Sand covers less than a fifth of the vast Sahara; the rest is a harsh world of gravel plains, stark mountains, and dry salt lakes. A road sign (below) warns that sand often blocks the curve ahead. Most of the 1,770-mile trans-Saharan road route avoids sandy stretches where drifts form. Al geria expects to pave the remaining 900 miles of its share of the uncom pleted highway by 1976.