Oh, i completely understand that. That is a skybox correct? I have read/watched a few tuts on the subject and understand that's what i have to do. I think what i need to ask is: when building an the "cup" as you say Ant, can i lay down the terrain for the bottom of the "cup" the cliffs for the "sides" of the cup, fill the cup with "matter". When that is all done cap it with a skybox high enough to make it look like the sky texture is actually a sky. As opposed to this: Creating a huge "cup with a cap" first then building up the sides and then filling with matter.
Or did i just answer my question myself... or will either way work. Did both of those above statements have the same meaning, developing the same outcome just approaching it differently..?