The Caspian Sea is not usually associated with the story of Atlantis, but as early as the 19th century Moreau de Jonnès proposed the Sea of Azov as the location of Atlantis and that the Black, Caspian and Aral Seas were just remnants of a large ocean.
While this may sound like a wild idea, one modern researcher, Ronnie Gallagher, has written an important paper(b) supporting the concept (see fig.8).
Gallagher has suggested that, based on whichever data is used this enlarged body of water had been joined with the Black Sea/Mediterranean or spread even further north as far as the Arctic. His conclusions are mainly based on sets of strandlines identified at elevations of 150 and 220 metres above sea level in the region of the Caspian Sea(d). From these he extrapolated an enormous inland lake centred on the Caspian (150m) or if the 220m level is used it was a sea joined to the Arctic Sea in the North. Gallagher published a hypothetical Eurasian flood map based on these figures. However, it should be noted that Professor E. N. Badyukova has offered some critical comments regarding Gallagher’s claims(e).
In the 1950s, Sprague De Camp wrote [0194.88] of compliant scientists in Stalinist Russia claiming that Atlantis had existed on land now covered by the Caspian Sea.
Fessenden cites Strabo (Book 11:7;43), who recounts a tradition that the Caspian had been connected with the Black Sea by way of the Sea of Azov.
Modern proponents of Atlantis in the Sea of Azov have suggested(a) that at the end of the last Ice Age floods of meltwater poured into the Caspian Sea, which in turn escaped through the Manych-Kerch Gateway(c) into what is now the Sea of Azov, but at that time contained the Plain of Atlantis!
Immediately to the south of the Caspian are the Caucasus Mountains which have also had links with Atlantis proposed.
The Caucasus Mountains lie between the Black and Caspian Seas and contain the highest mountain in Europe, Mount Elbrus (Russia). In ancient times it was the location of several kingdoms of whom two were known as Albania and Iberia
Delisle de Sales was probably the first to suggest the Caucasus as the home of the original Atlantis, with refugees from there establishing Plato’s Atlantis in the Central Mediterranean. However, the greatest proponent of the Caucasus location for Atlantis was R.A. Fessenden who wrote an extensive multi-volume work  on the subject early in the 20th century.
More recently, Ronnie Gallagher, an admirer of Fessenden, has studied the Caucasus region, in particular, the hydrology of the Caspian Sea(a), where he identified strandlines up to 225 metres above sea level, which he considers to be evidence of a vast inland Eurasian sea at the end of the last Ice Age. In Azerbaijan, he also found cart ruts similar to those on Malta as well as stone circles on the Absheron Peninsula(b). Professor E. N. Badyukova has offered some critical comments regarding Gallagher’s claims(k).
Flinders Petrie also referenced Fessenden in his (1926) paper The Origins of the Book of the Dead(f), in which he concluded “that the cultural connections of the earliest Egyptians, as well as the physical descriptions in their mythology, point to the Caucasus region. When, further, we find there the names of the principal places of the mythology in their relative positions, it gives strong grounds for regarding that region as the homeland of the earliest civilisation of the Egyptians.”
A few years later, an article by M. A. Murray in Antiquity (Volume 15 – Issue 60 – Dec. 1941) noted that Petrie’s “opinion was based entirely on literary and philological evidence” resulting in archaeologists being slow to accept it. To partially counter this Murray offered two pieces of evidence in support of Petrie’s proposed Egyptian-Caucasus connection.(i)
However, I must point out that in 1874 Hyde Clarke delivered a paper to the Royal Anthropological Institute in which he claimed that the Colchians in the Caucasus had been an Egyptian colony(h). Clarke also employed language similarities to support his contention. So we can reasonably ask, who was right or were both Clarke and Flinders Petrie wrong?
A forum on Graham Hancock’s website offered some more discussion about an Egyptian link with the Caucasus(j).
The Amazons of Greek mythology are thought by some to have originated in the Caucasus and as late as 1671, Sir John Chardin reported that a tribe of Amazons existed in Georgia. Interestingly, a 19th-century photo shows two armed ladies from Armenia captioned as ‘Amazons of Armenia 1895’.
An added mystery was offered by Alexander Braghine, who recounted that “I was present when a former Russian officer of Georgian origin found himself able to talk with the natives of Vizcaya immediately upon his arrival in Northern Spain: he spoke Georgian, but the Basques understood this language.” [156.187]
Currently, Bruce Fenton has claimed the Caucasus as the home of giants. However, Jason Colavito has demonstrated the unreliability of his claims(c).
In the Krasnodar region of southern Russia hundreds (3,000 and counting) of dolmens are to be found on both sides of the Caucasus. Interestingly, they show a distinctive form of megalithic architecture(g).
I feel that the Caucasus will have a lot more to tell us.
(i) Antiquity, Vol. 15, Issue 60, Dec. 1941 p.384-386