I saw a pretty neat carrying case and playset accessoriy at my local Michaels store last time I dropped in. It was fashioned as a castle and was hinged so that the inside was revealed. It included a working drawbridge, in that it opened, and numerous windows, plus a draw/box where miniature or toy figures could be stored. This costs $19.99 but with their regularly available 40% off coupons, you could snag one for $12 plus tax. I'll have to keep this in mind for a future project. I'd imagine priming it in black then adding successive coats of lighter and lighter gray, begining with a dark gray of course, to make stonework. It might even be useful to make a couple of stamps of stonework patterns using the crenulations as a guide for the size of the stones. The interior would require a bit more work.