Fallen Sky Ridge
Fallen Sky Ridge is a widestretched area of northwestern Hellfire Peninsula populated by dangerous colossi. Its most prominent feature is an enormous red crystal which curiously plummeted from the sky.
The truth is that the crystal was purposefully planted into the earth in order to corrupt and summon the colossi with its inherent essence. The blood elves are behind this scheme, with Kael'thas being the ultimate mastermind and culprit.