Hi all!
Actually, there is an interesting theory that I have dug for a few months even if I have not found relevant pieces of information till now.
This hypothesis is assimilating Atlantis and Hyperborea, another lost civilisation from Greek mythos.
There are two clues that lead to this path:
1) Plato argued that he knew about Atlantis through the Egyptian priests of Pharaoh. But, Antic Egypt had suffered by the past an invasion by the so-called Sea People who would have come from the Northern sea i.e. the current Aegean Sea. So, some theorists have allegued that those Sea People can have been survivors of Atlantis fleeing the disaster and attempting to settle in another place. According to this theory, they could come from the North by sea and so might be from the Black Sea, which would make their country match with the mythological emplacement of Hyperborea also.
2) Plato notified that there was a channel to pass in order to rally Atlantis with both the Pillars of Hercules on each side i.e. the current Gibraltar channel. But, we must travel through the Dardanelles to pass from the Aegean Sea to the Black Sea still now, which imply to move between the Antic cities of Abydos and Sestos. And, Antic authors like Polybius genuinely compared this channel to the Pillars of Hercule as its counterpart as a boundary of the known world.
Plus, there are archeological discoveries like the Varna site that prove existence of a advanced, prosperous civilisation in this area around 100.000 years before our time.
Actually, they would have been ancestors of the Thracians, the Cimmerians or the Scythians.
I hope that all those elements feed up our brainstorming!
At soon!