Although Hades was the god of the dead, he was also considered the god of wealth because precious minerals came from beneath the ground. Hades' realm was divided into two parts, Erebus, where the dead first entered the underworld, and the deeper region of Tartarus, where the Titans were imprisoned. The underworld was divided from the world of the living by 5 rivers: Acheron, the river of woe; Lethe, the river of forgetfulness; Styx, the river of unbreakable oaths; Phlegethon, the river of fire; and Cocytus, the river of lamentations. 