The field in which Arthas is fought is on his throne and the area around it. However, if you were to fly to the top of Icecrown Citadel, it doesn't seem to be there. The area above that spire in the "real world" looks exactly like the battlefield on which you fight Arthas on. But of course, minus a throne.
Am I just seeing things, or are these two related in some way? Is Blizzard just lazy and decided to just not add the throne to the top of the "real world" spire? I need to be notified!