Really?
You mean Plato created Timaios and Kriteas as a great lie .
All of Plato's Dialogues use near-contemporary historical figures as mouthpieces. Hence Socrates showing up a lot. No one has any idea how much of what Plato attributes to Socrates was what Socrates genuinely said or would have said in those circumstances. In the specific case of Criteas, there's doubt over which Criteas he intends his character to be; it's generally considered not to be the politician who was one of the Thirty Tyrants, even though this is the Criteas who would have been contemporary with Socrates.
For sure Plato was a
brazen-faced liar.

Also he was a great Storyteller, he fictional created a great continent behind Atlantis, and was aware of the tropical zone were bananas grow. Really a accomplished liar.
Why wouldn't he be aware of the tropical zone? The Greeks knew of areas at least as far south as Ethiopia, which borders the eastern portion of the African humid tropics. Bananas would notably not have grown in that part of the world at that time, and certainly not 9,000 years before Plato - the very earliest date proposed for banana domestication is approximately 8000 BC, and it's more likely closer to 5000 BC. Bananas were probably first domesticated in Papua New Guinea, and naturally occur in the Asian tropics.
This is a moot point in any case, as nowhere does Plato appear to describe the fruit of the "orchard trees" that he mentions, and there seems no reason to imagine he either knew about or was referring to bananas. Nor does he make any obvious reference to the tropics - the only reference to the climate is "making use of the rains from Heaven in the winter, and the waters that issue from the earth in summer, by conducting the streams from the trenches". While the tropics have a wet-dry season cycle, so do the African subtropics with which the Greeks would have been most familiar - indeed the Nile Valley civilisation was built on this cycle.
If you actually go back to the original text, it is very light on detail, describing only the dimensions of the island (which are plainly incorrect - I ran across one piece noting that if an island in the west Atlantic had been that size, it would have extended to Mt Cameroon), its formation as a series of concentric circles (created directly by Poseidon, incidentally, a true mark of the story's historical reliability), and the fact that it has some mountains in the south. It mentions that animals and cultivated fruit were plentiful, but describes neither. Most of the modern elaborations attributed to it - such as bananas Plato almost certainly had no knowledge of - appear to be altogether absent from Plato's text.