This does, perhaps, seem a little odd, but it's something I've been thinking about for ages and ages (since starting the 'Fire in the East' project), and have tried to research, unsuccessfully, on more than one occasion.
Following the success of the siege game Paul and I put on yesterday, I find that I really want to make or acquire some fortifications suitable to represent a walled town or fortress from the Eastern Empire - if you say Dura Europos, you wouldn't be far wrong. Dura itself, of which there are plenty of photos, is somewhat tumbled-down, so the form the battlements took isn't clear. If anyone has any decent evidence or ideas, I'd be very happy to hear them...