If I remember correctly, Plato was referring to a story by Solon of his talks with an Egyptian priest. The priest said these events were 9,000 years old, and since Solon was before Plato’s time which was around 400 BC, this pretty much adds up to 13,000 years ago which ties in nicely with the possible cometary cause of the Younger Dryas major cooling event. Links anyone?
Comet Theory Collides With Clovis Research, May Explain Disappearance of Ancient People
Ice Age Ends Smashingly: Did A Comet Blow Up Over Eastern Canada? (Carolina Bays)