The pillar of salt was still there during Roman times. It was a tourist attraction. It might still be there even now, but the location has been forgotten. It might have been in Persia, which doesn't narrow the search all that much.
BTW, do you think the story of Lot's wife actual history or an allegory?
There are (and were) many Byzantine era shrines in the Dead Sea area to St. Lot. The Pillar of Salt is mentioned by quite a few people that traveled to that area. In fact, there are still formations called "Lot's wife" of large salt pillars that are very popular tourist destinations.
As to the Ark, well part of me really hopes it is true. Kind of a dream of mine. But I doubt it. Most old accounts of the ark place it in what is now Turkey (Plato, Eusubias, etc), so Iran isn't that probable.