How about a few different types of CAVES?
??
That is what I am missing.
I'm making my own by stacking rocks on one another but that isn't quite it...
It works but I mean neat mountains with maptextures,bushes and a few openings to get into them,maybe even a small base set up in them with defencepoints and such.....something that blends in the landscape.
I can't YET make them myself in O2 but some1 with experience could do it in a few hours flat I think.