War of the Ancients was the name of a speculated upcoming raid in the Caverns of Time, planned to be released some time during World of Warcraft: Cataclysm as part of the progression on to the fight against Deathwing. It was to feature a pre-Sundering Kalimdor, ten thousand years in the past, during the first invasion of the Burning Legion. With the release of official Patch 4.3 info, this raid appears to have been changed to a 5-man dungeon called Well of Eternity.