Mythical place, told of by Socrates (i think), where all people
work together in harmony. It was this ideology of a pure race and a pure place that led to the Holocaust in the Second World
War.
Also, the name given to an ancient Greek city, well known for its good
work ethics, which was
hit by a tidal wave a couple of thousand years ago.
These two stories are usually linked, and it is not known if Socrates meant that Atlantis was a real place or a spiritual ideal.