Legolas gazed ahead, shading his eyes from the level shafts of the new-risen sun. 'I see a white stream that comes down from the snows,' he said. 'Where it issues from the shadow of the vale a green hill rises upon the east. A dike and mighty wall and throny fence encircle it. Within there rise the roofs of houses; and in the midst, set upon a green terrace , there stands aloft a great hall of Men. And it seems to my eyes that it is thatched with gold. The light of it shines far over the land.
Ok, so it's not exactly a dike, but the vulcanism in Return of the King more than makes up for it. All in all, Peter Jackson did a fine job with locations- though it is hard to go wrong with mountains like New Zealand's.