Hell in Paradise Lost is the antithesis of Heaven. In a sense, Hell is an ironic parody of Heaven. Hell for Milton is literally the underworld. Heaven is the zenith of the universe, then there is the great gulf of Chaos and Night, and finally, at the bottom, underneath everything, is Hell.
The phrase associated with Milton's Hell that has occasioned much discussion is the statement that Hell, "As one great furnace flamed, yet from those flames / No light, but rather, darkness visible" (I, 62–63). The idea of flames that do give off light and darkness that is visible has troubled some commentators over the years. But, while one may grant that the phrase "darkness visible" is oxymoronic, it is also meaningful. Heaven, which is pure light, is also pure goodness. Hell is the opposite, pure evil and pure darkness, in fact a darkness so pure that it is visible, a contrasting quality to the blinding light of Heaven.
At first, Hell seems like Dante's place of miserable torment. The fallen angels wake, lying on a lake of fire, surrounded by sulfurous fumes. However, this first image of Hell is soon replaced by a second. The demons build a capital, Pandemonium, with a palace and a throne for Satan, contrasting with God's throne in Heaven. The demons also have contests, sing, and debate, so that Hell begins to seem more like Dante's Limbo, not such bad place except that it is apart from God. Both these images are aspects of Hell for Milton; it is a place of punishment and also a place where demons live in a manner that ironically imitates Heaven. The difference is that the demons' games, songs, and debates are all corrupt and have no true end unlike the absolute beauty and truth of Heaven.
