Some "alternative historians" believe that the Atlanteans were decendants of aliens who came to inhabit Earth after their native planet was destroyed.
Proponents of this hypothesis include Michael Tsarion and Zecharia Sitchin, who believe that a worldwide nuclear war wiped out most traces of this ancient civilization, sending its capital city of Atlantis far beneath the sea approximately 11,000 years ago.
"They interfered with the indigenous population of this planet," Tsarion says. "And, when I say 'interfere,' I mean genetically, biologically."
The idea that Atlantis would be found somewhere in the mid-Atlantic emerged during the late 19th century. American author and politician Ignatius Donnelly postulated that the lost civilization had been near the Azores. He based his theory on Plato's description of the continent as lying outside the Pillars of Hercules, which are commonly thought to be the Straits of Gibraltar.
In 1968, pilots flying over North Bimini Island spotted an astonishing geological formation of beach rock that was laid out in straight lines. This area, which came to be known as The Bimini Road, was thought by many Atlantis-seekers to be evidence of the lost continent.
In 2004, American explorer Robert Sarmast used side-scan sonar to discover an underwater formation 50 miles off the coast of Cyprus. The site sits atop a small mountain nearly a mile below the surface. Sarmast believes this site matches point by point with Plato's description of Atlantis.
Sarmast believes that the capital of Atlantis once sat atop a mountain, surrounded by shallow lakes in what was once a dry Mediterranean basin. Long ago, the Mediterranean sea level was lower because it was separated from the Atlantic ocean by a seawall in the Strait of Gibraltar. Powerful earthquakes breached the seawall, Sarmast claims, sending a tsunami-like wave streaming across the basin, flattening everything in its path — including Atlantis.
Having successfully mapped the site, Sarmast is mounting an expedition to launch a deep-sea submersible to take live pictures of it and remove a piece of what he believes is Atlantis.
Some seekers of Atlantis have set their sights on Antarctica, chief among them Argentine explorer Alex Chionetti. According to Chionetti, Antarctica was once located closer to the equator. Approximately 10,000 years ago, he insists, Earth's axis tilted, sending the continent of Atlantis drifting toward its present location at the South Pole.
Chionetti presents such evidence as the 500-year-old Piri-Reis map, which depicts what Chionetti believes to be the coastline of Atlantis. He also points to a 1976 Norwegian expedition to Antarctica, which allegedly found "mysterious structures" that he thinks are remnants of the Atlantean empire.
THE NAZI SEARCH FOR ATLANTIS
Under the guidance of Heinrich Himmler, Nazi party archeologists undertook ambitious expeditions to find the lost continent. According to Heather Pringle, author of The Master Plan, "Atlantis was the mythical homeland of the Aryan race."
Equally bizarre is the Nazis' hypothesis of Atlantis's destruction, summarized in Welteislehre, or "World Ice Theory." They asserted that six moons once surrounded Earth. Five crashed into the oceans, triggering ice ages, the last of which coincided with Plato's date for the destruction of Atlantis.
Because of these and other implausible hypotheses, and their connection to the Nazis' racial-purity experiments in concentration camps, the Nazis' search for Atlantis cast a shadow over future archeological efforts for decades after World War II.
Contemporary archeologists suggest that Plato's account of Atlantis's demise is an allegorical retelling of catastrophic natural disasters known in his time.
In 1967, off the island of Santorini, Greek archeologists found the lost city of Akrotiri, buried 4,500 years earlier in volcanic ash. In 2001, archeologists unearthed the ancient city of Helike, which had been destroyed by a massive tsunami spawned by an earthquake, just 20 years before Plato wrote his chronicle of Atlantis.
Could either of these sites be the original inspiration for Atlantis? That's what serious archeologists are seeking to determine.