In Greek mythology, Charon or Kharon is a psychopomp, the ferryman of the Greek underworld. He carries the souls of those who have been given funeral rites across the rivers Acheron and Styx, which separate the worlds of the living and the dead. Archaeology confirms that, in some burials, low-value coins known generically as Charon's obols were placed in, on, or near the mouth of the deceased, or next to the cremation urn containing their ashes. This has been taken to confirm that at least some aspects of Charon's mytheme are reflected in some Greek and Roman funeral practices, or else the coins function as a viaticum for the soul's journey. In Virgil's epic poem, Aeneid, the dead who could not pay the fee, and those who had received no funeral rites, had to wander the near shores of the Styx for one hundred years before they were allowed to cross the river. Charon also ferried the living mortals Heracles and Aeneas to the underworld and back again.

A katabasis or catabasis is a journey to the underworld. Its original sense is usually associated with Greek mythology and Classical mythology more broadly, where the protagonist visits the Greek underworld, also known as Hades. The term is also used in a broad sense of any journey to the realm of the dead in other mythological and religious traditions. A katabasis is similar to a nekyia or necromancy, where one experiences a vision of the underworld or its inhabitants; a nekyia does not generally involve a physical visit, however. One of the most famous examples is that of Odysseus, who performs something on the border of a nekyia and a katabasis in book 11 of the Odyssey; he visits the border of the realms before calling the dead to him using a blood rite, with it being disputed whether he was at the highest realm of the underworld or the lowest edge of the living world where he performed this.