One of the city’s best kept secrets, this free exhibition looks at the development of the famous British red pillar boxes at the larger site in Debden, and stamps, artwork, post office records and promotional posters and the like featured at the central London site in Farringdon. Fascinating.

Free, Mon-Fri 10am-5pm, selcted Sat 10am-5pm

Freeling House, WC1X 0DL

Tube | Farringdon