Hell - synonyms and antonyms

Synonyms
Abaddon
infernal regions, infernoperdition , place of torment, purgatory

Hades, lower world, grave,  ordeal, everlasting
fire, bottomless pit, misery, hell-fire, , nightmare, blazes, trial, abyss,
Gehenna
underworld
 nether world
wretchedness
pandemonium
fire and brimstone

Some general words sometimes referred to as hell:

anguish, difficulty, pit, affliction, torment, agony,limbo,suffering

Antonyms

Antonyms bliss, elysian fields, Elysium, empyrean, heaven, kingdom come, New Jerusalem, paradise, sky, Zion (also Sion)