I watched something on this stuff once before, it shed a lot of light on bible myths. Many places may have existed as object lessons that lend to "stories". How so? Likely there were two cities (such as these) that were destroyed, either in a war, or by rock falling from nearby volcano, or astroid as someone said, and as it was abandoned on a popular route, people would make reference to it along with the myth, to reinforce the "moral" they were trying to promote.
"see those burnt cities over there son, god burnt the shit out of them with fire from heaven because we didn't like what they did".
Also Lott's wife in the same vein. Along the sea shore there are these spires of salt, that you can clearly see would inspire vision of people turned into or were trapped in them. So you have a similar scenario.
"see that pillar of salt? that's lott's wife, she didn't listen and BAM! salt..."
This is not uncommon with bible myths or other culture's myths. Could finding prehistoric bones in Greece inspired things such as the Cyclopes? We know native Americans have myths for rock formations in the southwest, or for mountains in other areas. Because these mythological places exist, doesn't make the fantastic stories facts. Myths were reinforced by visible objects to explain them, not the other way around.