Brainwave: start with UNESCO world heritage sites to make sure I don’t miss anything stupid.  For instance, I had Rome, Venice and Florence on the list but not Naples, just outside of which is… Pompeii.  Yes, I’m a  mouthbreathing idiot.  So The Map is about to get a lot more densely populated, and then the whittling will start.

http://en.wikipedia.org/wiki/List_of_World_Heritage_Sites

OK. Wow. Shit.  Spain alone has like forty sites.  The map is going to get insane.  There’s no way I can see everything.  But okay, even if I plot it all on a map, and then find like a top 100?  Okay, I’ll just precis and map anything I’m particularly interested in.