Atlantis was and still is in Mauritania
"For these histories tell of a mighty power which unprovoked made an expedition against the whole of Europe and Asia, and to which your city put an end. This power came forth out of the Atlantic Ocean, for in those days the Atlantic was navigable; and
there was an island situated in front of the straits which are by you called the Pillars of Heracles; the island was larger than Libya and Asia put together, and was the way to other islands, and from these you might pass to the whole of the opposite continent which surrounded the true ocean; for this sea which is within the Straits of Heracles is only a harbour, having a narrow entrance, but that other is a real sea, and the surrounding land may be most truly called a boundless continent. Now in this island of Atlantis there was a great and wonderful empire which had rule over the whole island and several others, and over parts of the continent, and, furthermore, the men of Atlantis had subjected the parts of Libya within the columns of Heracles as far as Egypt, and of Europe as far as Tyrrhenia."
--Plato, Timaeus (360 B.C.), Jowett Translation.
I'm looking at an ancient Mauritania map... it runs to Numidia on the East, and goes to the Atlas Mountains in the South, beyond which is Gaetulia. It's definitely not bigger than Libya and Asia (Minor) put together... but maps would have to depend on chronology, since nations expanded and contracted... especially in land taken by the Moors of whom Sallust tells us in Catiline.
In any case, Mauritania was never an island. And it isn't outside the Pillars of Heracles... unless Iberia is also considered an island and outside of the Pillars... Interesting thought.
Strabo reports that the Iberian Turdetani "have an alphabet, and possess ancient writings, poems, and metrical laws six thousand years old." Strabo wrote sometime around when BC turned into AD... opinions vary. But an alphabet and laws, around 6000 B.C....
In 360 B.C., Athens was 9000 years old, and Egypt was 8000... a fascinating thought, that needs more thinking.