8,604 areas drawn on an equal land area map - software by author on an Archimedes computer.
This is the finest level at which it is possible to map the boundaries of postcode unit geography. The first half and next digit of the postcode locate these areas. One reason for drawing these here is to illustrate that software designed to depict the administrative geography of Britain should cope with other systems (or even other countries). The image also presents a nice picture of population density as the white boundaries coalesce.
Third print from a series of three.