Alexander build a wall to protect us from barbarians of Gog and Magog. He build this wall of stone and iron in the far northern mountains at the end of the known world. Its iron gates were controlled by the king of Hyrcania or the emperor of China. They kept at a distance the things that frightened us. They were built when the known world was small but fear of the unknown was huge and could move through the depths of the earth.
Impossible objects