When ancient Greeks died, they would have to cross a river named Styx. They would have to have to pay a fee to cross he river in a ferry. If they didn’t have a coin, then they would have to wait on the side of the river, grieving. On the other hand, if they did have a coin under your tongue, then Hermes would escort them to Hades.
The first stop in the underworld is judgment. There are 3 judges who see through impure souls. If the soul is not pure, it goes to Tartarus where the soul is punished. Good, pure souls go to Elizian, the land of the blessed.
In the early years of Greek mythology, Hades was believed to be a shadow were souls were seldom judged and they would grieve about losing their past existence. However, during the Greek Golden age, people had a better outlook on life. Pythagorus, believed that the after life was were souls are rewarded for their good behavior on Earth, by being with the gods. But another man, named Pluto thought that sinful souls would live in torture down in Tartarus.
To enter Tartarus, the souls would have to pass a serpent with many heads and they would also have to watch other sinful souls that were in pain from their punishments. There was a three headed beast names Serperous making all mortals stay out, and all souls stay in. He tears apart any man or soul that tries to leave. The underworld was a place where all souls would live out eternity.