Atlantis, originally mentioned by Plato, was supposedly an ancient culture and island that he said was destroyed by a natural catastrophe (probably an earthquake) about 9,000 years before Plato's own time. Plato's Timaeus and Critias are the only written mentions of Atlantis, in which he gives some information on the size and location of the Atlantis island. Atlantis might well be a work of pure fiction, however, possibly intended to illustrate Plato's philosophy on the ideal government.
With rare exceptions, such as Francis Bacon's book The New Atlantis, interest in Atlantis then languished for 2,200 years until the 1882 publication of Atlantis: the Antediluvian World by Minnesota politician and sometime crankish writer Ignatius Donnelly. Donnelly took Plato's account of Atlantis seriously and attempted to establish that all known ancient civilizations were descended from its high-neolithic culture.
Later esoteric writers such as Helena Blavatsy and Edgar Cayce proposed that Atlantis was a site where disembodied spirits incarnated into human bodies, with Cayce adding that the Atlanteans also had ships and aircraft powered by a mysterious form of energy crystal.
Geology has demonstrated that no continent such as Atlantis has existed in the mid-Atlantic, so later enthusiasts have placed it in a bewildering variety of places, ranging from Sri Lanka, Peru, and Scandinavia, to the supposed center of the hollow Earth!
Among those who believe in an historical Atlantis, the leading theory holds that Plato's story of the destruction of Atlantis was inspired by massive volcanic eruptions on the Mediterranean island of Santorini during Minoan times.
Recently, a theory proposed by J.M. Allen has focused attention on the Altiplano in Bolivia. Allen took Plato's physical description of the location of Atlantis and compared it to physical features found in the Altiplano, and he found that they matched Plato's description on almost all counts, but for a factor of 2. Allen reasons that this error makes sense because pre-columbian South Americans counted in base 20. Another piece of evidence that Allen cites is Plato's mention of a gold/copper alloy called "orichalcum" that is only found in the Andes. Allen also claims that the very name of the place, Atlantis, comes from two native american words, "atl" meaning "water", and "antis" meaning "copper". Supporters of the South American Atlantis also cite scientists finding evidence of cocaine derived chemicals, cocaine coming only from the coca plant found exclusively in South America, as evidence that there was pre-columbian cross Atlantic contact that could have lead to the tale of a disaster reaching the ears of Plato via Egypt. This theory is currently being investigated by Allen and others.
Another recent theory is based on a recreation of the geography of the Mediterranean at the time of Atlantis' supposed existence. Plato states that Atlantis was located beyond the Pillars of Hercules, the name given to the Strait of Gibraltar linking the Mediterranean to the Atlantic ocean. 11,000 years ago the sea level in the area was some 130 metres lower, exposing a number of islands in the strait. One of these, Spartel, could have been Atlantis, though there are a number of inconsistencies with Plato's account.
Yet another theory that fits in with geography of 11,000 years ago sites Atlantis in the Antarctic archipelago - technically in the South Atlantic Ocean - where it would have been drowned by the rise in sea level after the last Ice Age. How cold the local climate would have been is a matter for speculation. Troy, Minoan Crete (or possibly Santorini) and other ancient port cities are asserted to be colonies.
Atlantis has also been the subject of such films as the 1961 Atlantis, the Lost Continent, Disney's 2001 animated feature Atlantis, the Lost Empire, Gainax's Anime series Nadia: The Secret of Blue Water, The French film Atlantis - Le creature del mare, and many others. A complete listing of the appearances of Atlantis in modern media would be too extensive to include here. Jules Verne's classic 20,000 Leagues Under The Sea also included a visit to Atlantis aboard Nemo's submarine Nautilus.
Additional information on Allen's "Atlantis in Bolivia" theory:
Additional information on the 'Spartel' theory:
Ignatius Donelly's Atlantis: the Antediluvian World is available as an on-line Project Gutenberg text (#4032): see http://digital.library.upenn.edu/webbin/gutbook/lookup?num=4032
/Talk Recent underwater discoveries off the west coast of Cuba have led some to speculate on an Atlantean connection. See www.earthfiles.com for more information.