Plot of the Day. The Netherlands has a very fine grained and in many senses very good postcode system. People often try to use postcodes for geographical purposes, to cluster precincts. The PC system however is not meant for that. Here convex hulls around all 3 digit prefixes, which often overlap:
This plot by the way was made by feeding 7 million or so house shapes into boost::geometry & asking it to draw convex hulls around dwellings sharing the same 3-digit prefix postcode. boost::geometry is pretty bad ass. #C++