I made a start on the shelters and shacks last night. The picture (a slum in Rio) at the top is kind of what I'm aiming for though not that densely populated as this is a gaming piece and I need to leave space to actually move miniatures around.
I've added a watch tower to the highest part of the mountain complete with warning bell to be rung in case of attack....or at dinner time.
On the same mountain top we have the first shack built from pieces of scrap plastic card and balsa wood. I've made a roof but left it removable to allow miniatures to be placed inside.
Finally I've done a bit more work to the main entrance including a bill board which will have some sort of witty settlement name on it (just as soon as I've thought of one)
I popped into Hobbycraft on the way home from work tonight and lucked out on a large bag of balsa strips in the clearance sale which has now given me loads of raw building material.