The Imperial War Museums' aerial photograph collection, the 'Air Ministry First World War Official Aerial Photographs Collection', includes more than 133,000 original glass plate negatives of aerial photographs, which makes it the only one of its kind. The collection is known as the 'Box Collection' or the 'Dave Parry Collection', because of the wooden boxes that hold the negatives, and because of the pioneering work of one of the IWM's former curatord. The collection is accessible at the Imperial War Museums via an index card system linked to the map grid of the 1:40,000 maps developed by the Geographical Section of the British War Department (GSGS War Office).
Since the collection is the work of the air reconnaissance units of the Royal Flying Corps and Royal Air Force, it mainly covers British areas of operation. A large quantity of photographs are available of, in particular, the Ypres Salient and the Somme battlefields. The collection includes aerial photographs of the Belgian coast southward to beyond Péronne; but there are also photographs that have been taken up to more than 100 km behind the German lines. Spearheaded by research at Ghent University and with funding from the In Flanders Fields Museum and the Nord-Pas-de-Calais Region, approximately 20,000 images have been digitised (especially the region of the Ypres Salient and the Nord-Pas-de-Calais region) and can be accessed online via the IWM website.