As of 2014, there is no definitive proof that the so-called "lost city of Atlantis" existed. Without substantial evidence, many believe that Atlantis is a myth created by the Greek philosopher Plato over 2,000 years ago.
According to Plato's account from around 360 B.C., the city of Atlantis was located in the Atlantic Ocean, and composed of mountains in the north and plains in the south. Plato states that Atlantis sank into the seas in one day, following a failed invasion of Athens.
Those who believe Plato have searched the Atlantic Ocean looking for the lost city, while others believe he was writing about the island of Santorini, which suffered a great volcanic eruption around 1600 B.C.