Two questions need to be addressed in conclusion to this book. The first is the future direction of aerial photographic research and its value in contributing to an understanding of the past. To an archaeologist, the primary record is not written at all on paper—for the purpose of this book, it is on the land, and photographs are a primary record. In the view of prominent English archaeologist, Peter Fowler, aerial photography, systematic ground survey, and rescue archaeology in the last decade or so:

. . . have overwhelmingly demonstrated ... a range and spread of archaeological material... simply unknown to, and unconceptualised by, earlier generations of students. One is writing not merely of many new sites but of whole landscapes and indeed of superimposed landscapes.. . . ¹

Such a revolution in the availability of evidence poses challenges for analysis and writing of history.

The second concerns the manner in which changes come to be layered on the landscape, and how later activity may destroy the earlier. Unscrupulous destruction has been continually occurring in the past, as the aerial photograph record amply testifies. Can there be a duty on the present generation, through legislation, government programmes and landowner initiatives, to preserve the archaeological evidence of past human activity?