The river Eridanos /əˈrɪdəˌnɒs/ or Eridanus (/əˈrɪdənəs/; Ancient Greek: Ἠριδανός, "Amber") is a river mentioned in Greek mythology. Virgil considered it one of the rivers of Hades in his Aeneid VI, 659.
Eridanos (river of Hades) Wikipedia
When in Nonnus' fourth- or fifth-century CE Dionysiaca the vast monster Typhon boasts that he will bathe in "starry Eridanus", it is hyperbole, for the constellation Eridanus, represented as a river, was one of the 48 constellations listed by the second-century astronomer Ptolemy; it remains one of the 88 modern constellations.
There have been various guesses at which real river was the Eridanos: these include the Po River in north Italy, and the Rhone, in France. The Eridanos is mentioned in Greek writings as a river in northern Europe rich in amber. A small river near Athens was named Eridanos in ancient times, and has been rediscovered with the excavations for construction of the Athens Metro.
Eridanos is the name that has been applied by geologists to a river which flowed where the Baltic Sea is now, a river system also known simply as the "Baltic River System".