Forgotten Sands

The Forgotten Sands is a hidden area, accessed during the Pandemonium Event. It is also where the ultimate boss Über Duriel resides and the only place where he can be battled.

The area is accessed by transmuting the Keys of Terror, Hate, and Destruction in the Horadric Cube.

Background
This hidden realm is part of Lilith's plot to revive the Prime Evils. Lilith masterminded the revival of Diablo by manifesting herself in the mortal realm and performing a ritual of Dark Summoning. This ritual, long thought to be impossible by the most powerful mortal wizards, allowed Lilith to link with Diablo across realms, strengthening him until he was finally able to once again reincarnate himself in the mortal plane. Rage and a deep yearning for revenge boiled within the eyes of the Lord of Terror, and together he and Lilith resurrected the two remaining Prime Evils as well as Duriel and Izual, two of their strongest agents.

The Forgotten Sands are a particularly barren and ancient part of the Aranoch deserts. It is here where the last remaining relic of the Lord of Destruction - Baal's Eye - can be found. However, it is fiercely guarded by Über Duriel, Baal's most powerful servant.

Appearance
The Forgotten Sands appear exactly like the Canyon of the Magi, without the waypoint in its center. It monsters some insect monsters and Uber Duriel. Exploration of the area reveals that there are piles of gold all around the map.

The Forgotten Sands area is considerably larger than Tal Rasha's Chamber (where the original Duriel could be fought), making it somewhat easier to manoeuvre during the fight.

Trivia

 * This area's appearance is consistent with Act II, which is where Duriel originally appears.
 * This is the only area where the Baal's Eye is dropped.