Before Cataclysm, the Cleft Of Shadows had no roof, you could see the sky from it. When Cataclysm launched, the Orgrimmar Skyway was over the Cleft Of Shadows. The question is this: where did that big piece of land come from? Did Shamans assemble it? Was it a lucky land slide that happened to perfectly make a plateau?
Sorry if this has already been answered.