A couple of weeks ago I was a tad dismissive of Pavillon de l'Arsenal's Internet database of contemporary Parisian architecture. It still has those two text buttons which follow your cursor around like a puppy watching your hand rather than the stick you've just thrown, and it's still pretty rough and ready...Maybe it's all an ironic reference to the Situationist derive first devised by Guy Laborde an arrondissement or two away from the Arsenal itself.
But look, there are a number of web-based attempts at digital tour guides for architects, first pioneered in print by Architectural Design, more recently by Wallpaper. The digital versions include The Archi-Tourist which is a wiki, that is to say that users create and edit the content following a standard format. It's worldwide but it's a bit lacklustre.
Whatever, it's worth also checking out archipedia ' the free open content atlas for world architecture that anyone can edit.'(so it's another wiki) and the very pretty, initially at least, Archiguide .