Melvyn Bragg and guests discuss Plato's account of the once great island of Atlantis out to the west, beyond the world known to his fellow Athenians, and why it disappeared many thousands of years before his time. There are no sources for this story other than Plato, and he tells it across two of his works, the Timaeus and the Critias, tantalizing his readers with evidence that it is true and clues that it is a fantasy. Atlantis, for Plato, is a way to explore what an ideal republic really is, and whether Athens could be (or ever was) one; to European travellers in the Renaissance, though, his story reflected their own encounters with distant lands, previously unknown to them, spurring generations of explorers to scour the oceans and in the hope of finding a lost world. The image above is from an engraving of the legendary island of Atlantis after a description by Athanasius Kircher (1602-1680). With Edith Hall Professor of Classics at Durham University Christopher Gill Emeritus Professor of Ancient Thought at the University of Exeter And Angie Hobbs Professor of the Public Understanding of Philosophy at the University of Sheffield Producer: Simon Tillotson