The Mogu'shan Vaults was built during the Mogu Thunder King's rise to power to contain and protect a mysterious artifact. Previously a titan facility, the mogu converted the surrounding structure into a sort of shrine dedicated to the mogu empire. The complex houses many of the empire’s lost artifacts and is the resting place of the spirits of old mogu kings. The Engine of Nalak'sha, a powerful titan artifact used by the Thunder King, was once housed there, but it is unknown if it is still hidden inside the vaults or has been moved or destroyed.