Shrine of the Codex

Located on the south of the Isle of the Avatar, surrounded by high mountains, the Shrine of the Codex is built upon the former entrance of the Abyss. Two magical Stone Guardians protect the only entrance to the valley holding the shrine, allowing only those on a sacred quest to enter. The Shrine has often served as the repository of the Codex of Ultimate Wisdom.

Age of Enlightenment
Some years after the Avatar descended to the depths of the Stygian Abyss to become the first Britannian to view the Codex of Ultimate Wisdom, the Great Council removed the fabled book from deep beneath the land, and erected a shrine for it upon the Isle of the Avatar. There, in a valley protected by Stone Guardians, the Shrine of the Codex protected Britannia's most sacred relic. The seeming geological upheaval of this event seemed to have caused the Abyss to erupt, but then cease activity.

During Blackthorn's despotic reign, the Codex was still found there, and only those upon a sacred quest were allowed to enter its presence. The Codex would eventually serve to give the hero the Word of Power for dungeon Doom, and should one of the Avatar's companions fall prey to the torture devices of Blackthorn's prison, their cremated ashes could be found in the Shrine's presence.

Sometime later, during the Gargoyle invasion of Britannia, the Avatar would again visit the Shrine, and using the lenses and the flames of Infinity and Singularity, the Codex of Ultimate Wisdom would be sent to the void to assist in forging peace between Human and Gargoyle. Despite sitting directly atop the Great Stygian Abyss, the eruption of this volcano after the events of Ultima Underworld seemed to have left the Shrine mysteriously unharmed.

Age of Armageddon
During the Guardian's first attempt to invade Britannia, the Avatar would again visit the Shrine, but by this time it had fallen largely into disuse, with a strong black gate mysteriously guarding its entrance. The flames were no longer present, and the Shrine lay empty. Oddly, the entrance to dungeon Hythloth was now accessible from within the Shrine.

It was during the Avatar's final visit to Britannia that the Shrine of the Codex would for the last time play an important role. The Shrine had been moved deep within a cavern on the Isle of the Avatar, and the flames of Singularity and Infinity once again burnt brightly. The Avatar was able to access the holy tome for a final time with the help of the Human and Gargoyle lenses.

Trivia

 * The locations of the Shrine of Humility and the Shrine of the Codex were inverted in Ultima VI. They later reverted to their original locations in Ultima VII.
 * The Keyring Mod for Ultima VII modifies the shrine so that it bares a greater resemblance to its appearance in Ultima VI.