Naz'anak: The Forgotten Depths is a cave located far beneath Icecrown Citadel. Normally the player's first time visiting here will be through the quests  /  , where the result of lighting the fuse on several Saronite bombs knocks the player off the rail, and in to the large saronite-lined hole, eventually falling down through a crack in the ice into the water in Naz'anak.
Also, it has a rich biodiversity of fungal plantlife, and seems to be the home of at least two dozen Faceless ones. The Altar of the Ebon Depths is also located within here, which was previously required by tailors to create Ebonweave cloth.
Naz'anak is divided into two small rooms, each with a small lake in their center (one of which the player falls in). The rooms are connected by a nerubian hallway that contains the Altar of the Ebon Depths.
Some fans speculate that Naz'anak is actually the Icecrown exit of the Azjol-Nerub tunnel which Arthas and Anub'arak used as a shortcut to Icecrown (seen in the mission "Ascent to the Upper Kingdom"). This would make sense, since it is a cavern very alike to the Old Kingdom, and it holds Faceless ones.
If this is so, its location also would indicate that it is a part of the Upper Kingdom of Azjol-Nerub.
- Faceless Lurkers: Their battle cry indicates that they are somehow aligned with Yogg-Saron. Their blood is needed for the quest  .
- Matthias Lehner.