Mail Rail was a huge network of automated electric trains running right under Central London, carrying mail between main railway stations and sorting offices much faster than along the congested streets above.

Construction of the railway began as far back as 1914, with the tunnels dug by hand. However, work was put on hold during the First World War, when the tunnels were used to store and protect art treasures belonging to the National Portrait Gallery and Tate Gallery.

When the railway finally opened in 1927, the railway consisted of six and a half miles of tunnels below ground connecting the West and East ends of London, cutting the journey time across London from a few hours to just 30 minutes.

It was an engineering marvel. Mail Rail ran almost non-stop, night and day, transporting over 4 million letters everyday until 2003.

For more than 100 years, Mail Rail was hidden from view.  Today, guests to the Postal Museum are able to experience this secret space as part of their event and explore a vital part of Britain’s communication network before instant messaging and social media became the norm.