Ben
Jane,
About the Brussels and Wallonian heritage institutions, I don't know
if there is something. Belgian guys may have some information about
it, I'll ask them.
For the French part, there is already a page :
http://en.wikipedia.org/wiki/Monument_historique. I'll try to add more
information about the history but I have few of time. The page in
French is pretty complete : if you translate it, it will be easier for
me to correct it.
For the European Heritage Days in France, I think the website will
come. It was online before summer, with the old version. If you need
any more information about France, please ask me.
Benoît