Atlantis (in Greek, Ἀτλαντὶς νῆσος, "island of Atlas") is a legendary island first mentioned in Plato's dialogues Timaeus and Critias, written about 360 BC.
According to Plato, Atlantis was a naval power lying "in front of the Pillars of Hercules" that conquered many parts of Western Europe and Africa 9,000 years before the time of Solon, or approximately 9600 BC.
After a failed attempt to invade Athens, Atlantis sank into the ocean "in a single day and night of misfortune".
Scholars dispute whether and how much Plato's story or account was inspired by older traditions.
In Critias, Plato claims that his accounts of ancient Athens and Atlantis stem from a visit to Egypt by the legendary Athenian lawgiver Solon in the 6th century BC.
In Egypt, Solon met a priest of Sais, who translated the history of ancient Athens and Atlantis, recorded on papyri in Egyptian hieroglyphs, into Greek.
Some scholars argue Plato drew upon memories of past events such as the Thera eruption or the Trojan War, while others insist that he took inspiration from contemporary events like the destruction of Helike in 373 BC or the failed Athenian invasion of Sicily in 415–413 BC.
The possible existence of a genuine Atlantis was discussed throughout classical antiquity, but it was usually rejected and occasionally parodied by later authors.
Alan Cameron states: "It is only in modern times that people have taken the Atlantis story seriously; no one did so in antiquity".
The Timaeus remained known in a Latin rendition by Calcidius through the Middle Ages, and the allegorical aspect of Atlantis was taken up by Humanists in utopian works of several Renaissance writers, such as Francis Bacon's New Atlantis and Thomas More's Utopia.
Atlantis inspires today's literature, from science fiction to comic books to films. Its name has become a byword for any and all supposed advanced prehistoric lost civilizations.