Sometime near the fifth millennium b.c., exhausted men push heavy boulders across a cavern opening. Cold mountain wind bites exposed skin. Surviving family members huddle on a rocky ledge. They scan the dark valley below with quiet dread. A heavy physical weariness settles into their bones. They pull thick animal skins tight for warmth and find mild comfort in the rising sun.
The patriarch is dead. Seth and his siblings stand near the summit. They face a choice between isolation and starvation. Down in the valley, the descendants of Cain forge iron tools. Up on the ridges, the remaining family guards the Cave of Treasures. The high altitude offers natural defense against raiders. A working laborer required roughly eighty pounds of grain a month to survive a harsh winter. The rocky soil yields very little food. The family trades an empty stomach for physical safety.
The sealed cavern functions as a crude bank vault. Thick rock and packed earth protect gold and myrrh from scavengers. Necessity turns a simple mountain fissure into a fortress. Frightened people look at heavy stones and see impenetrable security. The Creator leaves his followers to drag their own rocks across their own doorways.
A heavy stone door keeps wolves out but it also traps the sheep inside.
Early human settlements frequently chose defensive high ground over fertile lowlands. The broken stone markers of these ancient camps remain scattered across the ridges.