It's been announced that London's Mail Rail -- once used to transport post beneath the capital -- will open to the public in 2017.
London's Mail Rail —
It's been announced that London's Mail Rail -- once used to transport post beneath the capital -- will open to the public in 2017.
Kevin Taverner/CNN
Operated by the UK's Royal Mail postal service, the service opened in 1927. It ran until 2005.
78 years of service —
Operated by the UK's Royal Mail postal service, the service opened in 1927. It ran until 2005.
CHRIS RATCLIFFE/AFP/Getty Images
A sign displays the network of Mail Rail stations beneath the city. These were situated beneath the city's main postal sorting depots.
Hidden world —
A sign displays the network of Mail Rail stations beneath the city. These were situated beneath the city's main postal sorting depots.
Kevin Taverner/CNN
A map shows the layout of some of the network, which stretched 23 miles from east to west across the city.
Mail map —
A map shows the layout of some of the network, which stretched 23 miles from east to west across the city.
Kevin Taverner/CNN
Although the service was abandoned, mail workers still hosted occasional visitors, giving them rides in converted carriages.
Abandoned carriages —
Although the service was abandoned, mail workers still hosted occasional visitors, giving them rides in converted carriages.
Kevin Taverner/CNN
At Christmas they took groups of children to visit Santa through tunnels painted snow white and bearing festive murals.
Festive visits —
At Christmas they took groups of children to visit Santa through tunnels painted snow white and bearing festive murals.
Kevin Taverner/CNN
The network doubled as a rail track beneath the Vatican for the 1991 Bruce Willis action movie "Hudson Hawk." This engine was painted yellow for its starring role.
Starring role —
The network doubled as a rail track beneath the Vatican for the 1991 Bruce Willis action movie "Hudson Hawk." This engine was painted yellow for its starring role.
Kevin Taverner/CNN
At the height of operations, the fully automated service was carrying four million letters each day.
Heavy traffic —
At the height of operations, the fully automated service was carrying four million letters each day.
Kevin Taverner/CNN
The rail tunnels, 70 feet (21 meters) below the streets of London, resemble miniature versions of London's Underground passenger network.
Deep beneath the streets —
The rail tunnels, 70 feet (21 meters) below the streets of London, resemble miniature versions of London's Underground passenger network.
Kevin Taverner/CNN
Some of the existing engines will be converted to carry passengers on a short stretch of track when the Mail Rail opens to the public.
New beginnings —
Some of the existing engines will be converted to carry passengers on a short stretch of track when the Mail Rail opens to the public.
Kevin Taverner/CNN