This Peak icon is encircled by Win Hill, Crook Hill, Derwent Edge and Ladybower Tor from which it takes its name. Work began on the reservoir in 1935 and despite major difficulties carried on during the Second World War. Famous for the training ground for the Dambusters squadron the filling of the reservoir began on 18th March 1943 and was finally opened by King George VI on 25th September 1945.