If, on the contrary, Plato had said that Atlantis built pyramids, it would be difficult to deny that Plato's account of Atlantis was a veritable fact, for to maintain that Plato’s account was fictional would mean that Plato, by pure chance, happened to invent a story about a prehistoric pyramid building civilization—precisely the civilization whose existence is pointed to by evidence only available in modern times—at a time when there was no evidence to suggest that such a civilization should have existed.
But using this logic, Yoon proposes that there is in fact an ancient motif that would prove that Plato was telling the truth about Atlantis: concentric circles. Yes, one of the most basic of geometric forms is somehow proof of a lost civilization.
Yoon doesn’t quite manage even this low bar for proof, however. In trying to gather examples of concentric circles, Yoon resorts to spirals, which are pointedly not the same as concentric circles. In the end, he tries to argue that a Google Earth artifact in the Caribbean that resembles concentric circles must be Atlantis.
And yet he doesn’t stop to consider for a moment whether Plato would have other reasons for suggesting that the island of Atlantis had been carved by Poseidon in the shape of alternating rings of land and water. Many explanations exist, of various levels of believability. Many archaeologists have assumed that the explanation is related to the shape of the island of Thera (Santorini), and the unique ring shape left behind by the explosion of its volcano, destroying the Minoan city on the island. I don’t buy that personally. Those of a more mystical mindset see the three rings of land as representing either the three divisions of the cosmos (heaven, earth, and the underworld) or a Pythagorean triad.
Even if this isn’t what Plato had in mind, the fact that concentric rings occur outside of Plato’s Atlantis narrative in places where they would have been known to him undercuts the illogical supposition that the existence of concentric rings prove that Atlantis must have existed.