Background[]
Atlantis was a kingdom that sank beneath the sea in a disaster centuries ago. It is said that the inhabitants were transformed into Tritons and other sea creatures.
Behind the scenes[]
The destruction of Atlantis is described as having been 'eons' ago or several centuries ago. The centuries reference would seem to indicate it occurred less than a millennia before QFG5. Eons is less specific, either meaning an indefinite but long period of time (an age), or in geologic/scientific reckoning, often millions of years, a billion years (the latter meaning is 'unlikely' in this situation).