I personally believe Atlantis is just one of many stories based on the (apparently archetypal) "sunken island/continent" myth (other notable examples include Lemuria, Mu, Rutas, Cantre'r Gwaelod, Lyonesse and Hy-Brassail). These may be have been invented by story-tellers because the concept seems to be psychologically appealing to us, or they may be based on real lands which became inundated during human history, such as Doggerland and various others - which may also be the source of "Great Flood" myths.

People have been looking for it for a very long time and, with a bit of imagination and self-persuasion, they've located various places which could be Atlantis. However, my feeling, shared also by a majority of historians and scientists, is that Atlantis never really existed at all.