The Isle of Crypts is the very heart of Balance, where the Great Earth Serpent was said to dwell before journeying into the Void to bring Balance to the universe. The isle is meant to be the final resting place of all the Great Hierophants and the home of the Acolytes of Balance.
Isstanar mentioned the Isle of Crypts to the Avatar, and he was astounded that the hero had no knowledge of a place so important to their culture, although the hero was capable of reaching the island with the help of a serpent tooth supplied by Xenka. The Avatar traveled there to find one of the Eyes of the Serpent and to speak with Ssithnos, who was buried there. Here, the Avatar learned how to restore Balance.