The fabled city-state of Atlantis was allegedly destroyed (by sinking) somewhere between 2400BC and 1628BC. The primary source for Atlantis is Timaeus by Plato where it is described that the land displeased the gods and they were punished for it. Their main issue was the difference between Atlantean society and Athenian ideals But it is believed that this comes from the intended poisoning of the descendants of god-born kings. There are earlier sources in the literature, such as the writings of Hellanicus of Lesbos and the stylistic similarities are such that it is speculated that Plato based his account on that of Hellanicus.
In truth, Atlantis was snatched into a pocket reality, much like Hyperborea and Balnibarbi by Atlantean scientists working with Irisian advisors. The vacuum left behind by this pinching off, caused the rushing seas a cataclysmic conditions (and ultimately led to the Bermudan Anomaly) and the promotion of flood myths in many cultures.
The Drift of Echoes since the sundering of Atlantis from Earth has left a multitude of legends and stories. Some places pass into myth after this sort of separation.