Arcane Sanctuary

"Surely whoever, or whatever, built this was mad."

- Area description

The Arcane Sanctuary is a structure created by the Vizjerei Mage Horazon.

Lore
The Arcane Sanctuary is a vast structure. It is a giant platform floating in emptiness, surrounded by 'stars.' Narrow paths lead away into space, warping in strange ways as they loop back on one another, simultaniously above and beside themselves. The paths are just wide enough for two people to stand abreast. Within the Sanctuary, it's as bright as midday all the time.

An entrance to the Sanctuary exists from the Palace of Lut Gholein. Of note, the palace was once a Vizjerei fortress.

History
The Sanctuary was built by Horazon. Though a powerful summoner, Horazon feared that the Great Evils would punish him for enslaving their brethren. Thus, he created the Arcane Sanctuary, He believed that it would not only protect him from Hell's vengeance, but also allow him to continue his studies, free from the ravages of time and disease. He kept demons as slaves within the Sanctuary.

After the Darkening of Tristram, Jazreth gained entry to the Sanctuary via Lut Gholein's Palace.

In-game
In Diablo II, the Arcane Sanctuary appears in. It can be entered through a portal found on the lowest level of the Palace Cellars. Players then need to brave the many dangers of the Sanctuary in order to find Horazon's Journal. After reading the journal, a portal leading to the Canyon of the Magi opens.

The four paths are essentially the same layout, but each with a specialty: one path would contain portals/teleporters, another with stairs and platforms in an impossible geometric shape (which turns out to be the bane of the minions/mercenaries' pathing AI), yet another with regular stairs, and the final one with floor traps. The Summoner, along with Horazon's Journal and his summoning circle, can be placed in any of these arms.

The thinness of the walking space and the constant turning of the paths means that people with (such as possibly Horazon himself) would have an easier time than those without.

The area is filled with s, vampires, goatmen, and lightning spires. The description would be that of a set of cathedral-like stone platforms suspended in outer space; stars and a black void whiz by in the background.

When you and/or your battalion range-attack a Specter while it flies above the dark, surfaceless void, the Specter's corpse will fall and land in mid-air, on the same elevation as the floor you're walking on. Due to an apparent game programming oversight, the Specter's corpse will not fall forever through the bottomless void; the void has an invisible floor inaccessible to you and your cohorts that the corpse will land on.

Arcane Sanctuary, along with Arreat Summit, is one of the two locations in the game where the "perspective" video setting does not work. This is because perspective requires two layers to work with: one being the ground and the other for the objects (characters, trees, etc.) that move relative to it. The Arcane Sanctuary has one layer reserved for the background that shows the stellar void, hence perspective cannot work because both the foreground and objects share the other layer and thus cannot move relative to one another.

Trivia

 * Some aspects of the Arcane Sanctuary seem to be inspired on the work of M.C. Escher, for instance the impossible constructions in stairwells.
 * As stated in Horazon's Journal, the area around the book shows the six fake symbols that belong to the six fake Tal Rasha's Tombs. Players who completed Act II quests can use that information to find the real Tal Rasha's Tomb without trial and error, although reaching the Horazon's Journal involves trial and error as well.