Scientifically speaking, no one knows. Where everyone "thinks" Atlantis is tends to go through fads. At various times Atlantis has been in Antarctica, Bolivia, Turkey, Germany, Malta, and for a long time, the Caribbean. The current fad is that it is believed to be in southern Spain on the coast in what is now the Donana National Park. National Geographic and others announced that they found evidence that Atlantis was located in Doñana National Park, as did a 2004 study in the journal Antiquity. And Elena Maria Whishaw, director of the Anglo-Spanish-American School of Archaeology, published the 1929 book "Atlantis in Andalucia," (Rider & Company) which hypothesized that the region was a colony of Atlantis, so the case is building on this site.
The only thing most scholars agree, is that the part of Plato's description that said Atlantis has to lie beyond (as in west of) the "pillars of Hercules" which everyone pretty much agrees is in fact Gibraltar, and hence the reasoning goes the city has to be somewhere in the Atlantic, and hence, the name.
