Hunter-gatherers are traditionally believed to have lacked complex symbolic systems, social hierarchies, and the division of labor, three things you probably need before you can build a twenty-two-acre megalithic temple.
I, too, was in town on a pilgrimage, visiting a site that predates Abraham and Job and monotheism by some eight millennia: a vast complex of Stonehenge-style megalithic circles in the Urfa countryside.