I prefer the relics to be at a park or museum to be seen and cared for appropriately. I'll probably see these one day at Manassas but not likely would ever go to the Fairfax courthouse unless I get a requested invite from the local govementment.
I'm not inclined to visit the courthouse and cemetery of every town around although I've seen some neat artillery at those places. There is a nice group of 8" guns (IIRC) at the Mansfield Courthouse and the south side of Chicago has some nice guns in a cemetery. And of course Athens, GA courthouse has the famous double barrel cannon. And there are many more around.