Sodom and Gomorrah. Updated -- 15 February 2005 (and 6 June 2005) The absolute destruction and total obliteration of two cities to the point where there is minimal evidence that they ever existed, is a singular point in the story of Genesis.
Much is made of the alleged decadence of these two cities (but in comparison to New York or Los Angeles... who knows?). All of it does seem to be a bit overwrought. Enoch. Ancient civilisations. Mystical math.