Fort Southwick UGHQ Churchill's D Day Tunnels Portsmouth

This large underground headquarters was built in 1942 as a naval command centre. It is situated on Portsdown Hill beneath Fort Southwick, a large 19th Century Palmerston Fort. There are over a hundred rooms in the tunnel complex, and it was fully functional with offices, dormitories, Latrines, telecommunications etc, and it was utilised during WW2's 'Operation Overlord' as the main communication’s centre, used by the Royal Navy, to plot the progress of the Allied troops during the invasion of Normandy on D-Day and throughout the remainder of the War.
They were continually undated during WW2 and throughout the cold war up to the mid to late 70s.