What is that dark brown mountain-looking thing in center of area B7? Is it a large sand dune? A exceptionally tall plateau? A collection of rocks?
The book doesn't seem to specify what this is, and the scale makes the area too small for it to actually be a mountain (or even a large hill).
I seem to recall it being a large rocky outcropping the likes of which you might find sticking out of a desert. Don't remember where I think I read this but I do get the sense it's supposed to stick up out of the ground.
EDIT: There's actually a picture of it on the inside front cover. That large dome in the middle of the ship is the Habitat Dome