Pandemonium Fortress

"Can you believe this place? Did you ever dare to dream that you'd one day stand upon the crossroads between Heaven and Hell? This Pandemonium Fortress is truly miraculous."

- Deckard Cain

The Pandemonium Fortress is an ancient structure located in the heart of Pandemonium. It has changed hands many times.

History
The Great Conflict was waged over the Worldstone, which lay in the heart of Pandemonium. During the war, the archangel Tyrael ordered that a bastion be built around the object, the Worldstone itself kept within a guarded chamber. This stronghold came to be known as the Pandemonium Fortress. Over the course of the conflict, the fortress changed hands many times between angels and demons and as a result, took on structural and metaphysical traits from both the High Heavens and Burning Hells. Other outposts were maintained around the fortress as well. However, this state of affairs came to an end when Inarius and his renegades were able to steal the stone from the fortress, beginning a series of events that would lead to the creation of Sanctuary and its inhabitants, humanity.

It appears that even after agreeing to leave Sanctuary be, the powers of Heaven and Hell continued to war over the fortress for a time. The blood of thousands of champions of the Light were spent in these battles, many of such champions being mortal. However, as it no longer contained the Worldstone, the interest of Heaven and Hell in the fortress had severely waned. By the time of the Prime Evils' intended return to Hell, the Pandemonium Fortress was occupied by the forces of Heaven, and was their last bastion before the Gates of Hell. However, by this point, it had effectively been abandoned. Diablo, having passed through the Infernal Gate, passed through the fortress before entering Hell. Still, it was from the fortress that a group of heroes, at the behest of Deckard Cain and Tyrael himself, were able to venture into Hell and thwart Diablo's plan.

Over twenty years after these events, the fortress was occupied by Malthael's Reaper forces, killing its former inhabitants. The fortress was reshaped to reflect Malthael's will and massive soul constructs were built that powered the central core. In order to defeat Malthael, the Nephalem had to direct this soul power into themself, in order to enter the same state as Malthael and make him vulnerable to their attacks. Malthael was ultimately defeated.

Diablo II
The Pandemonium Fortress is the town hub of the fourth act of Diablo II. It has a doorway to the Outer Steppes which leads to the rest of Act IV.

Residents
These are the NPCs (Non-Playable Characters) associated with the Pandemonium Fortress:
 * Tyrael - The Archangel of Justice (Resurrects Mercenaries)
 * Deckard Cain - Horadrim sage (Identifies items)
 * Jamella - Champion of the Light (Trade, Healing and Gambling services)
 * Halbu - Champion of the Light (Trade and Repair services)

Quests
There are three quests to be obtained within the Pandemonium Fortress:
 * The Fallen Angel
 * Mephisto's Soulstone
 * Terror's End

Diablo III
The fortress is revisited in Diablo III: Reaper of Souls. It serves as the final area of the game. Writings of Inarius, Lilith and Malthael can be found within.

Areas

 * Heart of the Fortress

The fortress has been heavily rebuilt by Reapers; two levels are visitable by players (the third level is very small, and serves as a final chance to prepare for the battle with Malthael). The Interior is multi-tiered, composed of towers connected by narrow bridges. Death Gates can bring players over the edge, and Reapers often use the chains that support their structures to ambush heroes.

Inside, mostly Exarchs, Executioners, Winged Assassins and Anarchs are found; a few special events allow fighting demons as well. The fortress is filled with soul constructs, which serve no purpose for the gameplay, stacks of ammo, petrified angelic remains, packed siege weapons and tons of crates; presumably all of these remain here from the ages past. s and Freezing Gates are found across the fortress, both of which impact battles fought within the fortress (although the latter is capable of actually making combat easier for the Nephalem).

In Adventure Mode, a Level 2 waypoint is relocated to the middle instead of the entrance.

Residents

 * Enkasi (if playing as a Witch Doctor)
 * Guardian (if playing as a Barbarian)
 * Halbu
 * Halissa (if playing as a Demon Hunter)
 * Isendra (if playing as a Wizard)
 * Jamella
 * Master Crusader (if playing as a Crusader; gender matches that of the character)
 * Master Necromancer Ordan (if playing as a Necromancer)
 * Patriarch Anisim (if playing as a Monk)

Development
In terms of design, the fortress needed to encompass the feelings of being ancient and infinite without losing players in a way that would distract from gameplay. The designers took care to avoid creating the perception of being displaced or wandering in outer space. Time was taken to make it visually distinct from the Ruins of Corvus and Bastion's Keep. The level design of the fortress included elements of the Arcane Sanctuary from Diablo II.

Layout
The fortress changes its appearance, feel, and even layout to reflect its current owner(s). During the time of Diablo's awakening, the fortress was a bastion of the forces of the High Heavens and reflected their laws&mdash;no violence was allowed within its walls, and a magic barrier reached about 100 feet down the stairs to the Outer Steppes, which the fortress borders. Its structural alignment included the Hall of Heroes, a courtyard, and a gate through which the stairs that lead to the Outer Steppes could be reached.

The Island of the Sunless Sea
A quest that was cut from the original Diablo, Farnham mentions an "island where the Angels watch.". Extracting the wav files from the Diablo I disc's MPQ reveals that Farnham does, indeed, have an unused speech regarding this:

"Hey you there, c'mere, listen up!... Y'know 'bout the island where the Angels watch? Pick the right rocks, but ya better shield yer eyes -- shield everything! I know, 'cuz I been there, and -- mmmm, ale..."

Deckard Cain also has an unused speech file which speaks of the Island, transcribed as follows:

"Hmm. An island? Where Angels watched? Although Farnham's memory is often cloudy these days, that does seem familiar... perhaps the ancient Chronicles of the Sin War can help us... Ah! Yes! Here is something: In a time long forgotten, a sea of blue rested on the edge of the fiery netherworld. This was an oasis for those who acted as the watchmen over the gates of Hell. Angels and warriors of Light could use this place to heal themselves and gather their strength. It was also a staging area, where they could train and prepare for the Sin War. Legends speak of a trinity of rocks that hide the path to this... Island on the Sunless Sea."

Cain's description of the island seems to fit what we know of the Pandemonium Fortress. It is likely that the concept behind the cut "Island" quest in Diablo became what is now known as the Pandemonium Fortress in Diablo II.