Didn't they get carried away somewhere after the fight with the morbol? I believe the area is Dravania due to the size of the mountains in the area. There's no tall mountains near Mor Dhona and Coerthas is just small peaks.
But there's an area named Silvertear Falls just off the left of the map of Mor Dhona, maybe it's an unimplemented area that you zone into from there. I'll be disappointed if it really has been destroyed. The game needs areas like that to brighten up the terrain.