Sunwell

The Sunwell is a fount of power located upon the Isle of Quel'Danas, within the High Elf Kingdom of Quel'Thalas. It would sustain the arcane dependency of the High Elves, raise the Archlich Kel'thuzad and implode upon itself, cause the back-breaking addiction of the Blood Elf race and the creation of the Wretched, become a portal for Kil'jaeden's entry into Azeroth (Planet) and would later be reignited by the Naaru, M'uru.

Creation
When Dath'remar Sunstrider led his fellows in exile to the Eastern Kingdoms, vials of the Well of Eternity were poured into a lake within newly-founded Kingdom of the High Elves.

Destruction
As Prince Arthas Menethil led his brutal campaign across Lordaeron, he was instructed by the necromancers of the Scourge to resurrect Kel'thuzad's remains---housed within the burial urn of King Terenas Menethil II and protected by Lord Uther the Lightbringer. Carving a swath of destruction between himself and Quel'Thalas, Arthas would pave the Dead Scar and breach the three enchanted gates of the capitol, Silvermoon City.

When its Ranger-General, Sylvanas Windrunner was slain and converted, Arthas then arrived on the northern coast of Eversong Woods with no means to transport his Scourge to the Isle of Quel'Danas. Sylvanas had mocked him, stating that he would never reach the island---later proven wrong when Arthas created a bridge of ice between the coast and the isle. Upon placing the burial urn inside the well, the Archlich was born and the Sunwell had imploded. With its absence, the survivors became sorely addicted to magic and Prince Kael'thas Sunstrider would name them the "Blood Elf" race in honor of the deceased.