https://en.wikipedia.org/wiki/Greek_underworld
Geography
Rivers
Rivers are a fundamental part of the topography of the underworld and are found in the earliest source materials:[12]In Homer's Iliad, the "ghost" of Patroclusmakes specific mention of gates and a river (unnamed) in Hades;[13] in Homer's Odyssey, the "ghost" of Odysseus's mother, Anticlea, describes there being many "great rivers and appalling streams", and reference is made to at least four specific rivers.[14] H. A. Guerber assumed that the rivers where Charon sailed mirrored the sky in Greco-Roman thought.[15] In the wider mythological tradition, however, there are multiple bodies of water that are associated with the underworld (varying in number and combination depending on the source), the names of which can be understood to reflect specific associations with death.[16][17]
- The Styx can be considered the most prominent and familiar of the underworld rivers. It is the only named underworld river mentioned in Homer's Iliad[18] – our earliest mythological text – and three of the Homeric Hymns.[19] Not only is it an underworld river[20] but is also, more generally, the inviolable waters upon which the gods swear oaths[21] and a goddess in her own right (the daughter of Oceanus and Tethys).[22] In later traditions it often serves as the entrance to the underworld over which Charon (the ferryman of the dead) rows the deceased in order for them to enter the underworld. It is also known as the river of hatred.[23][24] There are several Styx-es in the real world: according to Herodotus, Strabo, and Pliny it was in Arcadia;[25] while Pausanias locates one in Nonacris.[26]
- The Acheron is the river of misery or river of woe.[24][27] It is mentioned in many early sources of archaic poetry but is less prominent and early than the Styx.[28]In some mythological accounts, Charon rows the dead over the Acheron rather than the Styx.[29][30] In some alternative sources Acheron is a lake (rather than/as well as the river)[31] and also functions as a synonym for the underworld.[32] Pausanias describes a river named Acheron in Epirus, Thesprotia, which flows into a swampy-lake and converges with a river Cocytus (like its Homeric counterpart) which Pausanias attributes as the inspiration for Homer's description of the underworld.[33] This site is also associated with specific instances of necromantic ritual and/or catabases from the mythic-past.[34] Likewise, later traditions note an Acheron river in Cumae, Italy, which was also identified specifically with Odysseus' necromantic/catabatic activity.[35][34]
- The Pyriphlegethon/Phlegethon is the river of blazing-fire (Pyriphlegéthōn being from the phrase puri phlegethonti, 'blazing like fire').[24] It has a single mention in Homer's Odyssey (Pyriphlegéthōn) where it is described as flowing into the river Acheron,[36] and then does not appear again in sources until Plato.[37]According to Plato, this river leads to the depths of Tartarus and is associated with punishment (in particular, people who hit their fathers and mothers). There was a river/field of this name near Cumae – maintaining its association with 'burning' due to the local hot springs[38] – which Strabo explicitly associated with the Homeric underworld.[39][34]
- The Cocytus is the river of wailing (from kōkuein, 'to weep, lament').[24] It too has only a single mention in Homer's Odyssey where it is described as a branch of the Styx that flows into the Acheron.[36] According to Plato, the Cocytus is circular and empties into Tartarus and is associated with the punishment of murderers.[40] It is also the name of a river in Thesprotia and Cumae which merges with the Acheron (see above).
- The Lethe is the river of forgetfulness, taking its name from Lethe, the goddess of forgetfulness and oblivion. In later accounts, a poplar branch dripping with water of the Lethe became the symbol of Hypnos, the god of sleep.[41] Some sources reference a plain of Lethe, rather than a river.[42]
- Oceanus is the river that encircles the world,[43] and it marks the border of the land of the living and the underworld.[44]
