So I am still working the learning curve on building terrain out of foam, this time trying to figure out how to do stone block construction. In this case, the base structure of the building was built out of foamcore, then I glued slabs cut and textured from XPS foam onto it in a reasonable pattern. (I actually used a stone building across from my office as an inspiration.)
In hindsight, it might be better with more windows. It looks like a jail or a stockade or a garrison of some kind, which isn’t a bad thing. I’m not 100% sure I like the effect–for my next stone building I am going to carve the foam instead.