In 1917 the American architect Andre Smith noted, ‘it is the aeroplane that has given to modern warfare a new weapon of defence and protection – camouflage … It is the garment of invisibility that is capable of not only protecting the individual soldier and the furniture of war, but of screening the movements of an entire army’ (Smith 1917: 469). Already during the First World War, camouflage – which offered protection from ground and air views – had become a vital necessity in warfare. Progress in aviation and aerial photography during the interwar years meant that by the Second World War concealment from the aerial view in particular not only had to be more sophisticated but that it also had to be practiced on much larger scales than ever before. To prevent structures and buildings on the ground from being visible and easily identifiable various measures were used for their horizontal and vertical concealment and for deception. They included the structures’ unobtrusive integration into the respective environment by means of carefully selecting their site, form, colour and texture, by preserving existing vegetation and planting new trees and shrubs on site, and by using artificial camouflage like netting, smoke and decoys.