The River Danube is the second longest river in Europe, which was known to the ancient Greeks as ‘Istros’. It rises in Germany’s Black Forest and after passing through many countries, including four capital cities, it eventually empties into the Black Sea.
A number of researchers have associated the river with Plato’s Atlantis. One of the earliest was Nicolae Densusianu who proposed that Atlantis had been situated in ancient Dacia, his native Romania. Over a century later some of his ideas have been revived by other Romanian commentators such as Adrian Bucurescu and Alexandra Furdui. Densusian’s nationalism is now frowned upon and there is an understandable suspicion that his modern Romanian supporters may have similar underlying motivations.
There is a gorge on the Danube known as the Iron Gates which provides part of the boundary between Serbia and Romania. Densusianu located the Pillars of Heracles at the Iron Gates, an idea supported by Ticleanu, Constantin & Nicolescu who place Atlantis further west on the Pannonian Plain. However, Ranko Jakovlievic expressed the view that the Iron Gates section of the Danube was the location of Atlantis!
Related to this, is the claim by ‘Sherlock’ that Pindar’s Olympian Ode 3 suggested that the Pillars of Herakles had been situated at the confluence of the Seva and Danube rivers near modern Belgrade(b) .
>A recent book  by Antonije Shkokljev & Slave Nikolovski–Katin also recount an ancient version of the ‘Labours of Hercules’ that took place in the Balkans.<
Christian and Siegfried Schoppe locate Atlantis east of the Danube Delta on Snake Island in the Black Sea an idea now adopted by George K. Weller(a) .