"This power came forth out of the Atlantic Ocean, for in those days the Atlantic was navigable; and there was an island situated in front of the straits which are by you called the Pillars of Heracles; the island was larger than Libya and Asia put together, and was the way to other islands, and from these you might pass to the whole of the opposite continent which surrounded the true ocean; " Plato......

Clearly islands such as Thera (Santorini), Crete, Malta or Sicily do not qualifly as Atlantis since they are not in the Atlantic Ocean, neither are they of the size of "Libya and Asia combined"

A sunken island in the Strait of Gibraltar would similarly not qualify: The Azores do not qualify on account of there has never been a sunken continent in the middle of the Atlantic Ocean and Antarctica... well, that has been under ice for hundreds of thousands of years so could not have supported a lost civilisation within Plato's timescale, besides in any case, it is not "in front of the straits (the Pillars of Hecules know known as the Strait of Gibraltar)and there is no geological evidence that it has moved from in front of the straits to where it is today.

That only leaves one candidate for the lost continent of Altantis and that is the continent directly oppostie the Strait of Gibraltar presently called America or to be more specific, South America This great continent was lost until re-discovered by Christopher Columbus in 1492, sailing west from Spain in an attempt to establish a route westwards by sea to the Indies.

above, the lost continent of Atlantis
now re-named South America
above, the lost continent of Atlantis was the way via other islands to the continent (Eurasia) surrounding the Ocean.

sailing to Atlantis

atlantisbolivia.org the lost continent of Atlantis is South America