Great North Road, Gibraltar

The Great North Road is a large road tunnel in the British Overseas Territory of Gibraltar. It was constructed by the British military during World War II inside the Rock of Gibraltar and remains property of the Ministry of Defence to this day. The road allowed lorries to travel from the north to the south of Gibraltar entirely within the Rock. The tunnel still contains the remains of World War II buildings such as Nissen huts, kitchens, offices as well as a generating station and period anti-submarine nets.

Tunnel data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).