There are many candidate theories. https://en.wikipedia.org/wiki/Flood_myth#Claims_of_historicity https://en.wikipedia.org/wiki/Flood_myth#Claims_of_historici.

There are many candidate theories. https://en.wikipedia.org/wiki/Flood_myth#Claims_of_historicity https://en.wikipedia.org/wiki/Flood_myth#Claims_of_historici... I like the Persian gulf one, after all the Sumerians who lived there later had a myth of which the Noah story seems like a retelling.