Lots of activity about cartography from the Brits in the last few weeks, it seems.
http://www.bl.uk/magnificentmaps/
All the maps in this exhibit are amazing examples of the art of cartography, but in particular, this map of London, hand-drawn, is one of the most unusual, obsessively detailed pieces I have ever seen.
http://www.bl.uk/magnificentmaps/map4.html