How British artist John Martin imagined the cities' end
British scientists believe they may have found evidence to support the Bible's account of the destruction of Sodom and Gomorrah.
But they think a natural cause, rather than God's anger, lay behind the calamity.
But now a retired British geologist, Graham Harris, believes he may have proved that the two cities really existed, and may have explained why they perished.
Unstable area
Dr Harris thinks Sodom and Gomorrah were built on the shores of the Dead Sea so that they could trade in naturally-occurring asphalt.
This tarry substance was used in ancient times to waterproof boats and to hold stones together in buildings.
But the ground next to the Dead Sea is very unstable, lying on the joint between two of the Earth's tectonic plates which are moving in opposite directions.
The area is vulnerable to earthquakes.
Flammable methane
Geological and archaeological evidence suggest that a huge one took place about four and a half thousand years ago - the time of the Biblical destruction.
Flammable methane pockets lie under the Dead Sea shores; the earthquake would have ignited them, the ground would have turned to quicksand, and a massive landslide would have swept the cities into the water.
Experiments carried out at Cambridge University have backed up this account.
But more conclusive evidence is still needed; not unless the remains of Sodom and Gomorrah are found under the Dead Sea's salty waters will the theory be proved.