Like the Greek epic poem the Odyssey, which traverses time and space, encompassing a number of disparate settings, Paradise Lost is set in several different realms: namely Heaven, Hell, and Eden (Paradise). Eden is part of the human universe, described as a "pendent world" that hangs on a "golden chain" attached to Heaven. In between Heaven and Hell is Chaos, a disorderly no man's land (or a "great gulf") guarded by the monstrous creatures Sin and Death, and presided over by Chaos personified. Hell is Satan's domain, created by God as a punishment for his disobedience, and Heaven is God's realm.
Milton's ornate descriptions of Heaven and Hell help to render vivid a key theme of the poem: the tension between sin, which dooms an individual, and goodness, which leads to grace. Hell is dark and fiery, a "dungeon horrible, on all sides round/As one great furnace flamed," representing perdition and punishment. Heaven, meanwhile, is vibrant, airy, and filled with light, symbolizing innocence and righteousness. God's throne in Heaven is "glorious brightness," and God himself appears as an orb of light, essentially indistinguishable from his throne.
Yet Milton's portraits of Heaven and Hell are nuanced, too, in unexpected ways. Hell, though usually darkened, can appear as dazzling as Heaven—as when Satan's fellow fallen angels rise up against God and his angels, and "the sudden blaze/Far round illumined Hell." Similarly, Heaven can appear Hell-like: "Heav'n resembles Hell" when God, in a dark mood, conceals himself in "[t]hick clouds and dark." These apparent contradictions help to emphasize another key theme of the poem: good and evil are not neatly separable, though they appear to be direct opposites. Thus, God can exhibit qualities of a tyrant, abusing his absolute power to punish Satan and humankind. Similarly, Satan—though corrupted—often exhibits positive qualities, too, like remorse and tenderness.
