The ancient city of Gobekli Tepe in Turkey, challenges what we know about the relation of  agriculture to the origins of civilization. Until its discovery it was believed that agriculture had to have been developed, before it was possible to have large societies. Since Gobekli Tepe is composed of massive stone monoliths, it was clearly built by an advanced society. But it predates the discovery of agriculture, so where did it s builders get their food?  Nevertheless, these monoliths show incredibly stone working ability, and may be aligned with celestial objects in the sky. https://www.ancient-origins.net/history/prehistory-revisited-0013376