Sorting rooms, London GPO

[Reference: Harry visited the sorting rooms of London GPO as mentioned in letter 13.]

Until 1998 there was a Postal Museum in the building that Harry most likely visited in London (King Edward Building).

The current postal museum in London has a significant website including information on mail sorting.

Loosely related: here is a link to the home of the Penny Black, the Bath Postal Museum. (Harry did not visit Bath but this site contains some interesting historical tidbits.)

This Georgian website may also be of interest.