Atlantis

Atlantis (Ancient Greek: Ἀτλαντὶς νῆσος, romanized: Atlantìs nêsos, lit. 'island of Atlas') is a fictional island mentioned in Plato's works Timaeus and Critias as part of an allegory on the hubris of nations. In the story, Atlantis is described as a naval empire that ruled all Western parts of the known world, making it the literary counter-image of the Achaemenid Empire. After an ill-fated attempt to conquer "Ancient Athens," Atlantis falls out of favor with the deities and submerges into the Atlantic Ocean. Since Plato describes Athens as resembling his ideal state in the Republic, the Atlantis story is meant to bear witness to the superiority of his concept of a state.

Quotes

 * For it is related in our records how once upon a time your State stayed the course of a mighty host, which, starting from a distant point in the Atlantic ocean, was insolently advancing to attack the whole of Europe, and Asia to boot. For the ocean there was at that time navigable; for in front of the mouth which you Greeks call, as you say, 'the pillars of Heracles,' there lay an island which was larger than Libya and Asia together; and it was possible for the travelers of that time to cross from it to the other islands, and from the islands to the whole of the continent over against them which encompasses that veritable ocean. For all that we have here, lying within the mouth of which we speak, is evidently a haven having a narrow entrance; but that yonder is a real ocean, and the land surrounding it may most rightly be called, in the fullest and truest sense, a continent. Now in this island of Atlantis there existed a confederation of kings, of great and marvelous power, which held sway over all the island, and over many other islands also and parts of the continent.
 * Plato, "Timaeus". Translated by R. G. Bury. Loeb Classical Library. Section 24e-25a