the British military constructed an underground bombproof city for 16,000 troops with enough supplies to last sixteen months, entirely within the Rock of Gibraltar. Facilities included a telephone exchange, a generating station, a water desalination plant, a hospital, a frozen food store, a bakery, ammunition magazines, a vast Royal Electrical and Mechanical Engineers shed where damaged vehicles and equipment could be repaired and roads. The road was built within a tunnel started when the 180 Tunneling Company of the Royal Engineers was created in 1940. The following year the 180 Company was joined by the 170 and 178 Companies.
The road tunnel
The tunnel starts at Maida Vale behind the old Casino at Europa Road and travels north behind the Rock Hotel to Brigade Headquarters and Doncaster Adit. At this point the road forks into several other minor tunnels dug to house kitchens and an ammunition magazine. The entrance to Wilson's Cave is also located here having been discovered while carrying out blasting the rock during the magazine's construction. The wide road continues north where it joins the Raglan Battery Shelter. The tunnel would allow military lorries to travel within the Rock. The Great North Road ends at the now abandoned Calpe Hole Generating station however, the tunnel system continues all the way to the north face of Gibraltar where the World War II tunnels join the Galleries dug out during the latter part of the 18th century, now known as the Great Siege Tunnels. With the addition of Fosse Way in 1944 it was also possible to travel from the tunnel system within the Northern Defences down the complete length of the Rock to emerge on the south east side of Gibraltar. After 1941 much of the spoil from mining was used for land reclamation into the Bay of Gibraltar to extend the runway of what is now Gibraltar International Airport to long and later to in length with a width of. Tunnelling created about 7,500 tons of spoil a day and the surplus was used for other land reclamation projects. The runway was required in order to carry out Operation Torch, the allied attack on French North Africa, from Gibraltar. In November 1942, U.S. General Dwight D. Eisenhower set up his headquarters within the Admiralty Tunnel to plan the Allied invasion of North Africa which would lead with the help of Montgomery's 8th Army to capturing the whole of North Africa.
In 1956 a dinner was served within one of the Great North Road's large side chambers to celebrate the centenary of the formation of the Royal Engineers. It was an apt celebration as the Royal Engineers can trace their history back to the Soldier Artificer Company which was formed on the Rock to dig Gibraltar’s first tunnels during its Great Siege. Today the tunnel system remains Ministry of Defence property and they are used to train troops for subterranean work. Guided tours can be arranged to view the remains of the World War II installations such as the kitchens, Nissen huts, the abandoned generating station and anti-submarine nets which would have been used to close off Gibraltar Harbour to protect the Allied ships berthed there. The approximately two-hour tour normally starts at Maida Vale, at an entrance behind the old casino on Europa Road, and proceeds through several large chambers visiting Brigade Headquarters and continues for almost arriving at the Calpe Hole Generating Station.
