After the Sundering, ten thousand years before the second war, Illidan had taken seven vials containing the waters of the Well of Eternity in order to create a new one. Illidan used three to create the new Well of Eternity, but it was not known what happened to the other four until recently. It was revealed that Kael'thas received one of the vials, as did Vashj.
Founding Arts introduce a compilation covering the flooded halls in Coilfang Reservoir, known as Serpentshrine Caverns as well as the core of the crystalline fortress Tempest Keep, The Eye.