On my way to Chislehurst Caves, I happened across this lovely - if leaning - Penfold letterbox. The model is named after its designer, John Wornham Penfold - an architect who also designed Goldsmiths College's main building in New Cross. (It was originally the Naval Training School.)
This was the standard pillar box design in the 1870s, and the first to be manufactured in red. However, it was expensive to produce so was replaced by a plainer, round model. About 150 Penfolds survive, but they are so popular that the Post Office have recently supplied about 100 replicas to various locations.
Readers of a certain age will recognise the name Penfold. Dangermouse's hamster sidekick was named after these boxes!