THIS is the 75th anniversary year of the Battle of Britain, when Britain was under threat from an invasion by Hitler’s Germany.

To mark the event, the 11 Group Operations Rooms Museum at RAF Uxbridge (also known as the Battle of Britain Bunker) will extend regular weekday opening to additionally include the third weekend of each month between April and August.

It was the home of Fighter Command No.11 Group, and it was in the Bunker that most of the RAF’s defence of Britain’s skies was co-ordinated during the Battle of Britain.

Decisions were made by the Bunker’s controller to scramble the Hurricane and Spitfire squadrons.

Today, the Bunker looks exactly as it did on September 15 1940, the most decisive day of the battle.

The original plotting map remains and visitors can follow in the footsteps of Churchill and Eisenhower.

Weekend opening dates are April 18-19, May 16-17, June 20-21, July 18-19 and August 15-16.

The Bunker would normally be open only on weekdays, with tours at 10am and 2pm. At weekends, there will be an additional noon tour.

They are fully guided tours lasting for around 1.5-2 hours and must be booked in advance.

The tours include a short film on the Battle of Britain followed by a presentation in the Plotting Room, describing how the battle in the sky above London and the South East was controlled from this historic room.

Visitors can also take time viewing the many artefacts in the Group Controller’s cabin and other rooms in the museum.

Displays include many artefacts from World War Two, as well as exhibits focusing on the Women’s Royal Air Force, Royal Observer Corps and the history of RAF Uxbridge.

All visits must be reserved by calling 01895 238154 or email to 11gpenquiries@btconnect.com to book places on a preferred date and time.