Gara had, perhaps, been a granite valley down whose middle the lava had flowed, slowly filling it, and arching itself up in a central heap. On each side were deep troughs, between the lava and the hillside. Rain water flooded these as often as storms burst in the hills. The lava flow, as it coagulated, had been twisted like a rope, cracked, and bent back irregularly upon itself. The surface was loose with fragments through which many generations of camel parties had worn an inadequate and painful track.