An abandoned underground railway is set to open to the public, revealing 100-year-old secrets of the Royal Mail.

The Mail Rail is located deep under the streets of London under Mount Pleasant, and was a hive of activity over a century ago, transporting billions of letters, postcards and parcels via underground trains.

The railway opens the public in July

The tunnels, which also feature platforms, run for 6.5 miles under London and meander around the Tube lines, linking six different sorting offices with the mainline stations of Paddington and Liverpool Street

When at its peak, the service carried more than four million letters, employed over 220 staff and operated for 22 hours a day.

The railway is located 6.5 miles deep under London

The tunnels were even used during the First World War, to hide the Rosetta Stone, which can now be seen in the British Museum.

The railway closed down in 2003 and is set to open to the public in July this year.

For more information on how to get tickets, just visit the website .

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