The story of Blasted Lands.
The Blasted Lands are a scorched red wasteland at the southern tip of the Eastern Kingdoms, and the place where the story of the Horde on Azeroth began. They were once the southern half of the Black Morass, a great marsh that also took in what is now the Swamp of Sorrows. Then the Dark Portal opened here, and the orcish Horde marched through it into Azeroth. The fel magic pouring through the gate dried and warped the swamp until nothing but cracked clay and twisted rock remained.
The portal has been closed and opened more than once since. Khadgar destroyed it at the end of the Second War; Ner'zhul's Horde rebuilt it to escape to Draenor; and when it was destroyed again, Khadgar and the Kirin Tor raised Nethergarde Keep beside it to make sure nothing would ever come through unannounced. The keep's Alliance garrison and mages still watch the dead gate from their walls.
The Burning Legion has not let go of this place either. After Archimonde's defeat at Mount Hyjal, the doom lord Kazzak gathered the Legion's remnants in the Tainted Scar, and his servants work to secure the land around him. Dreaded nathrezim have bound warlocks of the Shadow Council and the Dreadmaul ogres into a cult in the Legion's service, promising its leaders eternal life in exchange for their souls.
Written for this site from the game's lore. Further reading: Blasted Lands on Warcraft Wiki.

