So many castles...though it might take some research...how about something to assualt them? Catapaults? Or, in later years, canon? Assualt ladders? Battering rams? If you prefer buildings (or something like that), how about some great ornate bridges? Covered bridges? Or, experiment, futuristic bridges! Or, if you want to change from medieval things, how about Arabian tents/camps? Buildings like the Taj Mahal? Red Square type things like in Moscow? Or if you really want to let your imagination run crazy, futuristic city buildings. As always, though, with free things, enjoy yourself! All your stuff is amazing!