Valakas is slumbering in the dungeon beneath the Forge of Gods. To prevent him from awakening, you need to go to Valakas' Temple and explore it. Your party must have 15-100 warriors of Lv. 76 and higher. Weaker heroes won't be able to complete the mission. The raid lasts for 60 min., and every Wednesday the zone is reset, so you can only go there once a week.