- This article is about the mythological river. For the real rivers, see Eridanos (geology) or Eridanos (Athens).
Ancient references 
Hesiod, in the Theogony, calls it "deep-eddying Eridanos" in his list of rivers, the offspring of Tethys. Herodotus (III, 115) points out that the word Eridanos is essentially Greek in character, and surmises that consequently the river supposed to run around the world is probably a Greek invention. He associated it with the river Po, because the Po was located near the end of the Amber Trail. According to Apollonius of Rhodes and Ovid, amber originated from the tears of the Heliades, encased in poplars as dryads, shed when their brother, Phaeton, died and fell from the sky, struck by Zeus' thunderbolt, and tumbled into the Eridanos, where "to this very day the marsh exhales a heavy vapour which rises from his smouldering wound; no bird can stretch out its fragile wings to fly over that water, but in mid-flight it falls dead in the flames;" "along the green banks of the river Eridanos," Cygnus mourned him—Ovid told—and was transformed into a swan. There in the far west, Heracles asked the river nymphs of Eridanos to help him locate the Garden of the Hesperides.
Strabo disregards such mythmaking:
- One must put aside many of the mythical or false accounts such as those of Phaethon and of the Heliades changed into black poplars near the Eridanos (a river that does not exist anywhere on earth, although it is said to be near the Po), and of the Islands of Amber that lie off the Po, and of the guinea-fowl on them, because none of these exist in this area.
"Starry Eridanus" 
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.
Real river 
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.
Cenozoic river 
- Argonautica, iv.597ff.
- Ovid, Metamorphoses II, 367–380.
- Apollonius 4.599–603
- Strabo, Geography v,1,9.
- "the holy isle of Elektris", named for elektron, "amber", off the mouth of the Eridanos, was reached by the Argonauts, who were fleeing from the Colchians, in Apollonius of Rhodes' Argonautica, Book IV; their return trip from Colchis, in which they passed "the farthest reaches of the stream Eridanos" (iv.597), cannot be made to coincide with actual geography.
- Overeem, I., Weltje, G.J., Bishop-Kay, C. & Kroonenberg, S.B., 2002. "The Late Cenozoic Eridanos delta system in the southern North Sea Basin: a climate signal in sediment supply?" Basin Research 13: 293–312.
- Bijlsma, S., 1981. '"Fluvial sedimentation from the Fennoscandian area into the North-West European Basin during the Late Cenozoic". Geologie en Mijnbouw, 60: 337–345.