Scholars have seen multiple resemblances between the medieval Christian conception of hell and evil places in J. R. R. Tolkien's fictional world of Middle-earth. These include the industrial hells of Saruman's Isengard with its underground furnaces and labouring Orcs; the dark tunnels of Moria; Sauron's evil land of Mordor; and Morgoth's subterranean fortress of Angband. The gates to some of these realms, like the guarded West Door of Moria, and the Black Gate to Mordor, too, carry echoes of the gates of hell.
Some of the journeys down into the dark places of Middle-earth, too, have been likened to the katabasis of Ancient Greece, a descent into the underworld, as when Lúthien and Beren descend into Angband, or when Lúthien goes to the Halls of Mandos to plead with him to allow Beren to return to life, paralleling the classical Greek legend of Orpheus and Eurydice. These journeys into hellish places may also recall the medieval theme of the Harrowing of Hell, a story in which Christ descends into hell after his crucifixion, and sets the Devil's captives free with the power of his divine light. The Devil is paralleled by both of Middle-earth's dark lords, Morgoth and Sauron; Sauron is in turn supported by a range of demonic figures, including the Nazgûl who appear like the Devil as black riders on black horses, the fiery-eyed Balrogs, and the Orcs with their devilish habits and appearance.
- ^ Christopher 2012, p. 206.