Good fiction imitates facts. Plato declared that his Atlantis tale is philosophical fiction invented to describe his fictitious ideal state in the case of war. I suggest that Plato used three historical elements for this tale. (i) Greek tradition on Mycenaean Athens for the description of ancient Athens, (ii) Egyptian records on the wars of the Sea Peoples for the description of the war of the Atlanteans, and (iii) oral tradition from Syracuse about Tartessos for the description of the city and geography of Atlantis.