There’s nothing above the waves resembling Plato’s description of Poseidonia; either it’s under the Atlantic (which is exactly what he said; the shoal mud he describes remained in his own time according to his own report, a detail that Bettany Hughes ignores of course. As the Aegean was navigable in Plato’s time, and during the Trojan War, the pumice generated by the imaginary 2nd millennium BC supereruption has nothing to do with the description of shoal mud) and the island (larger than Libya and Asia combined, another detail that is not true of Santorini) was submerged suddenly (another detail that isn’t true of tiny Santorini) and may be entirely imaginary anyway. Perhaps some details were borrowed from diverse old folklore, I mean, doesn’t the Black Sea flood make sense as a source of some of that?.
I’ve always thought, considering the “Libya and Asia combined” tidbit, that if Atlantis had any basis in reality, it was from stories about early travels to the Americas.
One of Plato’s signposts was that Atlantis was beyond the Pillars of Hercules, usually taken to mean the straits of Gibraltar. However (and I’m reaching way back in memory on this one to a book I read 30 or so years ago), there is a set of islands nearby to Greece which was also known as the Pillars of Hercules, which could fullfil Plato’s requirements without having to venture from the Mediterranean Sea. Mayhap I’ll rummage around the internet tonight and see if I can find a reference to that.
(1) The Sumerians seem to have recorded an object which shared the same barycenter with Earth in the same orbit ~ it came close to Earth then jumped to a similar orbit with Venus, and someday it'll jump back. THis is reflected in the Sumerian story of Gilgamesh and his ginormous playmate Inkydoo. The data dates from BEFORE writing was invented and is in special symbolic notation.
(2)The escarpment keeping the Mediterranean out of the Black Lake basin broke in the same period of time.
Now, a question, how close did this asteroid have to get to Earth to appear to be nearly the same size as the Moon? Obviously it had to be pretty close. And, pretty big. The guy at http://www.barry.warmkessel.com/4related.html tells us of an expert in astrophysical phenomenon who says it was 3 miles wide ~ the body now crossing Venus' orbit is about 200 yards wide ~ however, 7,000 years ago if it passed earth as a large bolid just at the edge of the atmosphere it would have caused a stir ~ maybe a tsunami in the Eastern Mediterranean.