Neltharion's Vault



Neltharion's Vault is a large cavern found in Highmountain. It was here that the drogbar fitted the goblin-made plates to Deathwing. Stored here was the Hammer of Khaz'goroth and two sets of titan disks. With the help of Igrul the Scalebane, Huln Highmountain used the hammer to banish Deathwing to Deepholm.

The Slave Enclave leads to Obsidian Overlook, which lets non-dragons escape by flight path.

Speculation
This may be the lair where Neltharion hid the Demon Soul during the War of the Ancients. It is extremely likely that this is a section of Neltharion's Lair.