Fort Southwick UGHQ
Fort Southwick was the Under Ground HQ (UGHQ) for Operation Overlord which was the codename for the Normandy invasion on D-Day. Operation Overlord still remains the largest seaborne invasion in history, involving almost three million troops crossing the English Channel from England to Normandy in then German-occupied France.
Reports from radar stations were crossed-referenced with messages from shipping to provide an accurate picture of what was happening in the English Channel. This information was then plotted on a large table map at the Fort.