<Li> The Phlegethon is the river of fire . According to Plato, this river leads to the depths of Tartarus . </Li> <Li> The Cocytus is the river of wailing . </Li> <Li> Oceanus is the river that encircles the world, and it marks the east edge of the underworld, as Erebos is west of the mortal world . </Li> <P> In front of the entrance to the underworld live Grief, Anxiety, Diseases, and Old Age . Fear, Hunger, Death, Agony, and Sleep also live in front of the entrance, together with Guilty Joys . On the opposite threshold is War, the Erinyes, and Eris . Close to the doors are many beasts, including Centaurs, Gorgons, the Lernaean Hydra, the Chimera, and Harpies . In the midst of all this, an Elm can be seen where false dreams cling under every leaf . </P>

Where was the entrance to the greek underworld most commonly thought to be