The Post Office Railway—commonly known as “Mail Rail”—was an automatic electric railway created to speed Royal Mail delivery in London by bypassing the city’s congested streets. In the 2000s, Royal Mail deep-sixed the system and the site became a lure for adventurers eager to survey its ruins.

Early in the the 20th century, Royal Mail officials sought a way to make delivery faster. They found inspiration in Chicago’s subterranean freight train system. In 1927, after more than a decade of planning and work, the Post Office Railway opened for business. At its height, the system conveyed four million pieces of mail down a 6.5 mile underground stretch of track at speeds approaching 40 miles per hour with termini at Paddington and Whitechapel.

Its stations are closer to the surface than the tunnels, which were dug at a depth of 70 feet below the surface. This allowed workers to easily bring mail to the surface and the incline allowed for gravity-powered propulsion and braking. Around the middle of the 20th century, the system reached its peak volume, shuttling 4 million pieces of mail a day. As the century wore on, however, the mail volume dwindled, and the railroad went into the red.

In 2003, the railroad was closed down and abandoned and many of the entry points were sealed off.  It was long thought inaccessible, but after a group of partiers forced their way into the system others sought to find access. Since then, a few intrepid explorers, cameras in hand, have made the voyage underground. Gaining entry through mail sorting offices, explorers trekked through the tunnels and the ghost stations while trying to avoid detection by security cameras.

Their images reveal an empty but intact world. Much of the rail equipment appears in working order, sitting dormant, waiting to deliver one last love letter. 

Since the end of July 2017, the site has now been turned into the Postal Museum complete with a 20-minute ride on specially made miniature trains (which will start operating from 4th September 2017).