There were undoubtedly more than two cities engluphed in the "dead sea." In the valley of Siddim
were five - Adrah, Zeboin, Zoar, Sodom and Gomorrah.
The plain of Jordan was located in the "vale of Siddim
, which is the salt sea" (Genesis 14:3), described in Blake's Jerusalem (89:27) as the "Dead Sea by Sodom & Gomorrah[h]," cites which were flooded over (Gomorrah means submersion).
Because of the fertile land, the biblical Lot, the nephew of the Hebrew patriarch Abraham, selected the area of the cities of the Valley of Siddim
(the Salt Sea, or the Dead Sea) to graze his flocks.