Zigzagging across the northern Negev, the Nahal Beersheva scars the desert like the track of a giant snake. Sparse green shrubs cling to the channel for life, awaiting the rain that will turn this dry watercourse into a short-lived river. Eocene white chalk, a geological unit over 40 million years old, underlies some parts of the Negev and can be seen breaking through the surface at lower center and center right.
Exploiting such trough-shaped valleys by growing barley and wheat in the seasonally flooded areas provided one of the keys to successful Chalcolithic settlement in the northern Negev. More than 25 Chalcolithic villages have been found in the Beersheva valley.