Tutored in the Halls of Magic at the mystical city of Dalaran, sorceresses and priests diligently study their mysterious arts within the depths of the arcane sanctum. Over time, continuous study provides additional reserves of mana and the mastering of ever more difficult spells. It is also here that magical sentries may be called to allow the human towers to detect invisible enemy invaders. The arcane sanctum helped the blood elves and Kael'thas in the Warcraft III Frozen Throne human expansion campaign.