The new navy base was begun in 1893, but for some time the stone was brought by barge from the east side of the rock to
Gibraltar Harbour on the west side. The tunnel allowed stone from the quarries on the east side to be brought via a one-metre
narrow gauge railway to help construct the navy base on the west side. It had its own systems for fresh air, electricity, lighting and communication links to the outside world. The space now contains a very secure data storage facility previously owned by Vault Technology Services and now operated by
Continent 8. The size of the data storage facility is , which is split up into 80 separate rooms. It is not open to the public but it is possible to see from one end to the other and thus to observe how straight the tunnel is. The west end of the tunnel is accessible from
Queensway. ==References==