World war II Tunnels, Gibraltar
With the entry of Italy into the War, and a powerful Germany dominating Europe, the strategic importance of Gibraltar was intensified. The Garrison had to be increased in size and strengthened, including preparations made to deal with possible siege conditions. The problem was urgent and vital; space became even more valuable; stores, food, and equipment had to be built up and protected, and siege accommodation was required for the troops. A tunnel system would meet these needs and would give full protection from the then known types of air attack, as well as from sea and land bombardment.
At the start of the war, the civilian population was evacuated and the garrison was greatly increased in size. Numerous new tunnels were excavated to create accommodation for the expanded garrison and to store huge quantities of food, equipment and ammunition. The tunnelling was carried out by four specialised tunnelling companies from the Royal Engineers and the Canadian Army.
A new Main Base Area was established in the south-eastern part of Gibraltar on the Mediterranean coast, shielded from the potentially hostile Spanish mainland, and new connecting tunnels were created to link this with the established military bases on the west side.