Heh... Atlantis has been found a lot in the past hundred years. :') I've seen modern interest attributed to Ignatius Donnelly, author of "Atlantis, the Antediluvian World".
It's anyplace you want it to be.
It's a figment of the imagination and I believe it to be the invention of the Greek philosopher Plato as a lesson in morality and in what happens to a society that has grown arrogant in its ways.