Mordor is more than just a blighted landscape, it is an extension of Sauron's gangrened and avaricious soul. Every element of the land - the Dark Tower, Mount Doom, the Black Gates, Cirith Ungol, Minas Morgul, must manifest in some way the architecture of darkness and evil. The Gorgoroth itself is more than a parched plain, it is as if a storm-wracked sea suddenly solidified into stone, pitted and decayed but honed razor-sharp over time by the very negation of life the Dark Lord represents. Barad-dur's very foundations are anchored in the folly of Sauron, his wrath embodied in battlement piled on battlement, his power the mortar that holds stone to stone to impossible heights. The air itself is poisoned by his breath, and the livid sky is torn by the cries of his servants, the ground shakes with the iron shod tread of his armies. The land itself is in his image.
Can you put all this in one illustration? Of course not. And besides, film directors are all the same, they want you to combine close-up in a wide shot with three different dramas all in one. The image started off fairly simply. "It would be great to capture the vertiginous impossible nature of Barad-dur, but then of course a shot at the Red Eye wouldn't hurt would it, and while the background is still damp, how about squeezing in mount Doom? Oh yes, and a Nazgul or two would be nice while you're at it. And don't forget, lots of smoke, didn't I mention that the Ring had just fallen into the crack of Doom?" Directors...
The Art of the Return of the King