::I went with the geographical categories you suggested and have now made a VERY rough (!) first draft which you can see . But very unfamiliar with Luxembour geography, there is no doubt a lot of moving about to do (is "south-eastern" south or east and where do central or west go?). When I have been in doubt I have generally just parked them in the first group for now. Have a look before I do more about it and consider if those are the groups you want to go with. And feel free to do whatever modifications you find relevant of course. I think the best alternative is simply to have two categories: Castles and castle ruins. I believe other criteria will easily just lead to difficult destinctions and confusion.