Shrine of the Codex

Located on the southern reaches of the Isle of the Avatar and surrounded by towering mountains, the Shrine of the Codex stands upon the former entrance of the Great Stygian Abyss. Two magical Stone Guardians guard the sole entrance to the valley holding the Shrine, granting passage only to those on a sacred quest. The Shrine has often served as the repository of the Codex of Ultimate Wisdom.

Age of Enlightenment
Some years after the Stranger descended to the depths of the Stygian Abyss to become the first human to view the Codex of Ultimate Wisdom and, in turn, successfully attain Avatarhood, 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 warded by twin Guardian Statues, the Shrine of the Codex came to protect Britannia's most sacred relic. The seeming geological upheaval of this event appeared to have caused the volcanic Abyss to erupt, only to then fall dormant.

During the regent Lord Blackthorn's despotic reign, only seekers ordained with a sacred quest were permitted by the Guardian Statues to enter the presence of the Codex. The great tome would eventually serve to give the Avatar the Word of Power for Dungeon Doom, and should one of the hero's companions fall prey to the torture devices of Blackthorn's prison, their cremated ashes could be found in the Shrine's presence.

Two decades later, at the height of the Gargish invasion of Britannia, the Avatar would again have cause to visit the Shrine and, using the Vortex Cube in conjunction with two enchanted lenses to focus the flames of Infinity and Singularity, send the Codex of Ultimate Wisdom to the Ethereal Void as a means to facilitate the forging of peace between kingdoms 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
By the time of the Guardian's first attempt to invade Britannia, the Shrine had fallen largely into disuse, with solid metal gates now sealing its entrance. While the flames were no longer present and the Shrine lay empty, the Avatar entered its grounds seeking the entrance to Dungeon Hythloth, which had come to reside therein.

It was during the Avatar's final return to Britannia that the Shrine of the Codex would serve host to the hero's ruminations for the last time. On this occasion, the sanctum had been relocated deep within a cavern on the Isle of the Avatar, and the flames of Singularity and Infinity once again burned brightly. Within, the Avatar was able to access the mystic tome once more with the aid of the human and gargoyle lenses.

Trivia

 * The locations of the Shrine of Humility and the Shrine of the Codex are inverted in Ultima VI, reverting to their original locations in Ultima VII.
 * The Keyring Mod for Ultima VII modifies the Shrine to bear a greater resemblance to its appearance in Ultima VI.