The massive edifice of the Mohne Dam in Germany viewed from the compensating basin below. A huge hole was blown in the centre section, where the paler stone can be seen, in the early hours of 17 May 1943 by Lancasters of 617 'Dambusters' Squadron of the RAF - when the power station that had stood just below the dam was also destroyed. The attack was carried out using a secret "bouncing bomb" designed by Barnes Wallis. This picture was taken on a cool May afternoon 70 years later.