The entrance to the Caverns of Time has long existed in-game, nestled in the Tanaris desert and guarded by several rather unfriendly members of the bronze dragonflight. However, in the Burning Crusade, players will, for the first time, be able to venture inside the caverns and aid the bronze flight in its mission to safeguard the past. Inside, players will be able to help with Trall's escape from Durnholde keep, participate in the Battle of Mount Hyjal, and witness the original opening of the Dark Portal by Medivh. There's still a lot we don't know about this upcoming dungeon - level requirement? number of players needed? - but it already sounds exciting.