There is no doubt that something very dramatic happened some eight thousand years ago. In the space of a few generations the entire Scandinavian Ice Sheet as well as the Canadian Ice Sheet disappeared completely. Sea levels rose several hundred meters. North Africa went from lush and fertile, with lakes and rivers, to barren desert land. A large number of animals went extinct in the process, especially those with habitats close to the vanishing ice sheets.
Most of the population of North Africa had to move due to drought, while people in places like Doggerland and Sundaland were uprooted due to flooding. Under such terrible conditions, any civilization that might have existed at the time would have been greatly reduced or wiped out entirely. This would in turn have given rise to legends of great floods, paradise lost, and cities disappearing into the sea.
The fact that we have concrete evidence for a climate catastrophe lends credibility to the legends, including the possible existence of a lost ancient civilization, predating the Sumerians by several thousand years, spanning the world from Egypt to Peru. Such an empire would explain the curious similarity in ancient building techniques found in places like Crete and the Andes alike. The use of polygonal stones as building blocks in locations separated by enormous distances, as well as similarities in stone cuttings and various megalithic constructions, indicate communication across vast distances.
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This all points to a relatively advanced civilization with trading routes across oceans, which in turn lends credibility to the legend of Atlantis. The location of this legendary city would most likely be in an area that is today submerged by water, but which was at the time a port at sea level. Areas of interest are therefore places along the shorelines that existed during the ice age. As we get more detailed maps of the seabeds around the world, the location of this legendary city may reveal itself. As archaeologists turn their attention to the seafloor, many settlements, towns and cities may be found. If so, the evidence of an ancient lost civilization would prove conclusive as such settlements would predate the Sumerians by thousands of years.