The Mulberry harbours were innovative, portable structures developed by the British Admiralty and War Office during the Second World War. These temporary harbours were engineered to enable the rapid offloading of military cargo onto beaches where permanent port facilities were unavailable.
Designed in 1942, the harbours were constructed in total secrecy. Following the initial landings in June 1944, prefabricated sections were towed across the English Channel from southern England. These were installed off Omaha Beach and Gold Beach, supported by old ships sunk to serve as breakwaters.