Arcane Vault

Arcane Vaults are mystical buildings built by the Alliance of Lordaeron and the mages of Dalaran. They are stone chambers.

Aftermath of the Second War
One is the store of the Kirin Tor's mightiest of relics near the heart of the Violet Citadel.

During the days of the Invasion of Draenor, the Arcane Vault of Dalaran was raided by Teron Gorefiend in order to steal the Eye of Dalaran.

Third War
Garithos used the Arcane Vaults in Dalaran as cages to hold Dalaran's experiments. When the blood elves were trying to escape to Outland he had his Elite Guard open the vaults so he could release the experiments on the blood elves to try to prevent them from escaping.

Wrath of the Lich King
Arcane Prisons, created by Malygos during the Nexus War, resemble them greatly.