Pillar at Göbekli Tepe The huge limestone pillars arranged in rings at the Paleolithic site Göbekli Tepe are somewhat humanoid in shape, and the carvings are of dangerous animals, including lions, boars, foxes, snakes, vultures, and scorpions. The structure required enormous skill and effort of the people who built it, and clearly had great importance to them. (Vincent J. Musi/National Geographic Creative)