Altar of the Ebon Depths
From WoWWiki
The Altar of the Ebon Depths is located in Naz'anak: The Forgotten Depths[55.8, 86.2]. Prior to patch 3.0.8 tailors needed to be at the altar to create [Ebonweave]. Now Ebonweave is created at the Maw of Neltharion in Dragonblight.
To access the altar jump into the pit located below Icecrown Citadel at [54, 86] in Icecrown. The altar is surrounded by Faceless Lurkers who are level 79-80, and you can not mount in The Forgotten Depths, so you will likely have to fight them before you can make your Ebonweave.
