building=yes is a searchable and linkable index of every single
building=yes in OpenStreetMap (OSM).
A web page for every building in OpenStreetMap!
every single way means every single way as of late-January 2011.
⇦ What's that over there to the left? Why that's Untitled Building #2170790601 and others near it. It's in Éguilles, Provence-Alpes-Cote d'Azur, Bouches-du-Rhone, France.