Santorini/Thera may have been the factual basis for the Atlantis legend, and was the probable cause [Tsunami] of the end of the Mnoan culture, and dominance, of the eastern Med.
Actually, the caldera of Thera (nice rhyme) is prehistoric; the bay opens toward the Greek mainland, and no signs of any tsunami have ever been found there (or for that matter, on Crete); eventually, the Mycenaean Greeks took over Minoan areas and trade routes; ashfall from Thera has been found in Crete, but only on the eastern end of that island, and the maximum depth of the ash is 5 millimeters; and perhaps most importantly, the Minoans didn't curl up and die for at least 80 years after the supposed disaster (or nearly 200 years, if one wishes to believe in the 17th c BC date for the eruption being pushed nowadays). The only historical account of an eruption is Strabo's, and that eruption took place about 200 BC.