Plato's account of a vanished civilization, swallowed by the sea in a single day and night some 11,000 years ago, is the only ancient source for Atlantis, and this Naked Science episode tracks the modern hunt for it across four candidate sites: Malta, the Bahamas, Greece, and Cuba. Ignatius Donnelly, whose 19th-century writing turned an obscure fable into a worldwide obsession, gets credit for starting the search in earnest. Researchers and tour guides walk the film through underwater ruins and above-ground temple sites, checking each location against Plato's details of the city's layout and rituals. The film also follows the odder threads in the story: the Nazi expedition to Malta chasing a supposed Aryan origin myth, and psychic Edgar Cayce's prediction that Atlantis would resurface near the Bimini Islands. Skeptical and credulous voices both get airtime, and the episode never settles on a single site, leaving the comparison between the four candidates as the real takeaway.