Custom Areas? (Warcraft Private Server)

Yes, my friend just downloaded a custom area, place, for his private server, which i am currently a Admin on, and he summons me to this weird place, not like ive ever seen before, in real game, or even ANY GMisland, its all white, and square, you can only get there by .recall command, Now, How do i add my own Custom area, Ive searched google for hours, and i give up, SO can anyone possibly tell me What i can do, or tell me a site where i can download Custom areas. :excl: