A Lancaster bomber has carried out a flypast over the Derwent reservoir to mark the historic World War II raid on German dams.
The dam, in the Hope Valley in Derbyshire, was one of the sites used by airmen for practice runs ahead their mission.
Today, the RAF Battle of Britain Memorial Flight and 617 Squadron will recreate history by flying over the twin towers of the reservoir.
More than a third of the men who went on the raids, which required them to fly just 60ft above the ground, never returned.
After the flypast at the reservoir the aircraft will continue on to Chatsworth House to carry out another for members of the public gathered for the historic moment.
The flypast is one of several events taking place to mark the anniversary of the daring Dams Raid of May 16-17 1943 during the Second World War.
Only one of the original 133 pilots - 96-year-old Les Munro - is still alive.
In Staffordshire, the Royal British Legion will create a Field of Messages at the National Memorial Arboretum in Alrewas.
More than 10,500 cardboard crests carrying written messages from supporters will be on display at the memorial throughout the day.
Later, a sunset ceremony will take place at RAF Scampton, near Lincoln, where the crews set off from on their mission 70 years ago.
Veterans and invited guests will gather for the event, which is set to include a further flypast by the Battle of Britain Memorial Flight and 617 squadron.
The raid, carried out by 133 airmen in 19 Lancaster bombers from the specifically formed 617 squadron, was an attempt to cripple a major part of the Nazi war economy by carrying out attacks on three dams in the industrial heartland of Germany.
Fifty-six of the men did not return from the mission, which required them to fly the Lancaster bombers at just 60ft above the ground - incredibly low when compared to the 250ft aircraft must fly at nowadays - in the dark across northern Europe.
The top-secret mission, codenamed Operation Chastise, was led by wing commander Guy Gibson and was credited with boosting morale across Britain.
The planes, armed with scientist Dr Barnes Wallis' bouncing bombs, flew to the Ruhr Valley either side of midnight on May 16, 1943.
The Mohne and Eder dams were breached during the raid and the Sorpe damaged.
The attack was immortalised by the 1955 film starring Michael Redgrave and Richard Todd.
Even with the loss of life, the operation was hailed an incredible success at the time but in recent decades historians have downplayed its effects.
Les Munro, the last surviving pilot of the raid, said he believed the raids were justified due to the effect on morale in Britain.
Speaking to the BBC, the 94-year-old, who was born in New Zealand, said: "I believe from an operational point of view they were very successful.
"They had achieved the two major primary targets, they had damaged Sorpe - but not perhaps as great as Barnes Wallis had anticipated - but coming back to the general feeling the effect on the British morale was really significant and I think from that point alone it was justified and can be categorised as successful."
BBC Radio 2 are broadcasting Chris Evans' Breakfast Show live from RAF Scampton tomorrow to commemorate the anniversary.
Dermot O'Leary and Jeremy Vine will present a Friday Night Is Music Night concert live from Biggin Hill Airfield.
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