The convention in 3D design is that -x is west and -z is south. There was an early screenshot from MM8 (IIRC) that showed the coords displayed in the upper middle of the world screen. It's not in our archives; perhaps you can find that somewhere.However, don't be surprised if some of the indoor maps are rotated from what you would expect to be their normal orientation. This was the case in MM9; specified maps where created in one way and then rotated by the engine to suit the final design. That will probably be the case in MM6-8 as well.
