The technique of aerial photography, widely recognized as of immense
value to field archaeologists, had been little used in Ireland, although
the relatively slight disturbance of land by modern ploughing or
industrial development makes Ireland a particularly suitable region for
the identification of ancient features by this method. The results of
the surveys carried out by the Cambridge Committee for Aerial
Photography between 1963 and 1968 are nevertheless surprising. Many
ancient earthworks have been revealed by differences in soil-colour or
crop-growth, and the natural and man-made environments of these and
other prehistoric and early Christian settlements can be fully
appreciated. The pattern of settlement emerges over a wide area, as does
the character of large and complex sites such as Tara, while detailed
oblique views pick out smaller structures invisible on the ground.