Those things sound like pretty important factors. Probably more so than the flatness actually (I know some towns/settlements nearby that are build on some ridiculously steep slopes now I think about it...).

I'll probably come up with a better way of placing buildable locations later. I got my A* system up and running now (well,walking anyway), and it's actually churning out some entities which, with a bit of imagination, could be mistaken for the basic layout of towns...the brownish splats is where the buildings would be...

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