I absolutely adore this rendition of the Ghostgate. Makes you wonder what caused Beth to cut down on such "original" Velothi and Tribunal imagery... Even though, not all of it here makes sense. (The Crescent Blade being held high in the middle) Can anyone explain that?
The Ghostfence is also awesome! If you look, the curved blades work better on many levels, helping explain how the Ghostfence completly formed a Dome around Dagoth Ur. (If that actaully happened, but it's looks cool, and thus not boring and therefore right) Heh, notice also the statue of Mephala on the left Dome. Yeah, it's often the little touches that make a game.
But the size is collosal. Compare the picture (and the little people on the ground there) with the size of the actual http://hosted.planetelderscrolls.gamespy.com/ral-jiktar/images/ghostgate.jpg where the doors are nearly half the height of the towers themselves, and you probably understand the reason why this awesome design was unfeasible.
EDIT: Oh, it is there.