After the First World War, the British Government brought miners from Scotland, Wales and Durham over to Malta in order to excavate a four-mile underground tunnel from Senglea (near Porto Salvo) to Marsa via Corradino. This tunnel was intended for underground workshops to service the Naval Dockyard. During World War II this tunnel also served as a shelter for Admiralty employees while some one thousand Senglea residents were also allowed to dig out shelters in some parts of the tunnel which criss-crossed beneath the entire length and breath of Senglea.