Geophysical investigations with the georadar in the middle of Athens at Syntagma square and the discovery of the subterranean river Eridanos

During extensive geophysical exploration in the middle of Athena for the location of archaeological remains, an unexpected geophysical finding was revealed. The 80 l\AHz monostatic antenna of the georadar was utilized around the Square. At Metropoleos Street, in the extension of Philellenon Street and parallel to it, in five different and parallel vertical sections, the image of a river was depicted. The minimum of the river bed is at 6 m below the asphalt and its width is about 10 m. There is another possible palaeobed 30 m wide at 14 m depth below the level of the pedestrians. This river is the legendary Eridanos mentioned by ancient writers such as Hesiod, Plato, Strabo and Pausanias. It was associated with the earliest traditions of the Hellenes and its location and direction is associated with important buildings of classical Athena. Up to now its very existence, position and direction was doubtful. The river seems to originate from the Lecabettus hill rolling towards lower elevation, intersecting Syntagma Square and meandering towards the West part ofthe city.