Let us be clear: There is no archaeological evidence for the existence of any place called Atlantis. There is no city remains, no walls, not even a potshard that has anything to do with the mythical Atlantis.
The sole and primary source for the legend of Atlantis is the dialogs of Plato. In Timaeus, Plato gives the location and describes in some detail the geography and history of Atlantis. In Critias, Plato tells us that Atlantis became an aggressive power, launching wars conquest and enslaving many people in and around the known world at that time. In a final desperate battle an alliance of Free states, lead by Athens defeated the Atlantean forces. Then, the gods disgusted by the immoral conduct of the Atlanteans wiped the vast island off the face of the Earth in a day and night, using earthquakes and tidal waves to scour the world clean and causing the island to sink below the waves.
Timaeus and Critias followed Plato’s Republic in order of composition. It is clear that Plato was making a political point in his story of Atlantis. In the Republic, he described what he considered to be the ideal society. In the story of Atlantis, Plato offers the counter example and tells what happens when societies become corrupt.
The modern myth of Atlantis was created by Ignatius Loyola Donnelly in Atlantis: The Antediluvian World published in 1882. It is in this work we see the start of modern Atlantis myth. Donnelly’s Atlanteans were god-men, that when their homeland was destroyed moved into other parts of the world and became the models for gods, demi-gods and legendary kings and queens.
Further Helena Blavatsky, glomming on to Donnelly’s ideas, created the notion that the Atlanteans also had airplanes and explosives and were otherwise highly advanced. So-called “Psychic” healer Edgar Cayce claimed to have had psychic knowledge of Atlantean texts which assisted him in his prophecies and cures.
This is of course pure pseudo history, with no kind of evidence supporting this theory. As one scholar puts it: “It is only in modern times that people have taken the Atlantis story seriously; no one did so in antiquity.”*
The latest and most reasonable theory is that the story of Atlantis was inspired by the eruption of Thera, now called Santorini, and the subsequent fall of the advance Minoan culture on the island of Crete.
*Alan Cameron, Greek Mythography in the Roman World, Oxford University Press (2004) p. 124
Sources:
Alan Cameron, Greek Mythography in the Roman World, Oxford University Press (2004)
Garrett G. Fagan, Archaeological Fantasies: How Pseudoarchaeology Misrepresents the Past and Misleads the Public Routledge (2006)