Except Plato says the opposite. He said it was beyond he pillars of Hercules, which would be in the Atlantic, not in the Mediterranean. Hence the name “Atlantis”.
Except he doesn’t actually. Because the whole story is an allegory. His description of the location is no more telling people where a real place is than Lovecraft’s description of R’lyeh.
Oh geeze, I just realized in 2000 years gullible are going to be looking for R’lyeh. And Innsmouth. Etc etc. Oh boy, Lovecraft really screwed up the future.