It’s Atlantis. Everyone knows the basics: an advanced civilisation on a large island or small continent in the Atlantic Ocean, sunk beneath the ocean in a single day.
The Atlantis story originated in two works by Plato, the Critias and the Timaeus. These tell the story of Atlantis – created by the sons of Poseidon, ruled the world as an economic superpower, and finally destroyed by the gods of Olympus for its hubris.
Of course, so far as anyone can tell, Atlantis never truly existed. It was a myth, a parable regarding the dangers of arrogance and pride.