Sunwell

From wow.incgamers.com

"For millennia the mystical pool of energy known as the Sunwell fueled the potent magic of the exiled high elves. The Sunwell's inexhaustible power permeated the elves and infused them with a constant supply of arcane energy. For generations the high elves protected and cherished the well, benefiting from its powers even when outside the borders of their homeland, Quel'Thalas." - WoW EU Patch 2.4 Information

Since corrupted by the Death Knight Arthas, the Sunwell is now a prominent feature of the Sunwell Plateau.