DO take a ride on the Mail Rail
Go and learn about the secret underground railway built beneath London, linking Post Offices from Paddington to Whitechapel and delivering mail until its closure in 2003. A ride on one of the Mail Rail trains (made for carrying millions of letters, not humans) will have you both feeling like big kids in no time.
When is it? Open Thursdays, Fridays and Saturdays. Where is it? The Postal Museum and Mail Rail, 15-20 Phoenix Place, WC1X 0DA. Book your tickets here.