The Island of the Sunless Sea is an uberlevel found in the Glacial Trail in Act 5. It has two bosses Malic and Lucion, and is notable for the massive amount of gold dropped by enemies there.
The place where angels watch, an underground cave miraculously illuminated by sunlight. Was once the staging ground of the heavenly hosts for their crusades into the abyss. When the holy legions were defeated and forced out of the dimension by the forces of Hell, a few human worshippers remained behind to stand vigil. However, heavenly magic is too powerful for mortals to tolerate for long. The mutated, wretched remains of the human defenders were found and embraced by the mighty Lucion, son of Mephisto.