Thus, if we accept that the "Pillars of Heracles" are the straits of Gibralter, we are left with the conclusion that anything "beyond" is fair game. Thus, if Plato referred to the Ocean (a combination of the Pacific, Atlantic and the Indian) what was he referring to?
In looking at other clues, Sundaland certainly is a strong contender. Especially when one considers the Plato's words of it being "navigagable" in those days, as opposed to after a volcanic explosion in the sea, which is unnavigable by boats years afterwards...
What do you folks think?