While there may not seem to be a connection between the archaeologist and the aero- plane, the aerial view of the countryside can sometimes lead to fascinating discoveries. The exhibition presented here shows some spectacular examples of recent documen- tation of archaeological sites in Great Britain, where so-called aerial archaeology has a long tradition. Only some of the activities of man in the past have left traces which are visible on the surface, most of them have been levelled and covered by earth. Some of them may be visible due to the surface relief creates shadows when the sun is low. These form, function and spatial arrangement of shadow-sites may then be interpreted. The outlines of the features of the site may additionally be enhanced by blown snow lying in hollows or the way it melts. Remains of a second type covered by soil may be recorded on aerial photographs by soilmarks or cropmarks. The former are caused by ploughing bringing to the surface layers of differently-coloured soil. The presence of buried archaeological features affects the growth and colour of crops and thus observation of these effects can reveal sites.

Aerial photographs can produce a huge amount of information on archaeological sites. They allow the discovery of new, unknown sites, aerial photography allows the documentation of known sites and monitoring their state of preservation. It also creates an important basis for the assessment the spatial layout of sites and their type and function, and also allow a determination of the relationship between the site and its natural environment.

Aerial photography has been used in Great Britain on an increasing scale recent decades, and many impressive discoveries have been made. Since the beginning of its use the technique has

been used mainly as a research tool. With the passage of time, the role of aerial photography as a tool for the protection of archaeological sites has become increasingly recognised, and at present this role dominates. In Great Britain several thousand photographs are taken annually.

The method can be used also for documenting other remains of the past, such as for example palaces, parks, urban layouts, industrial monuments, fortifications etc. In recent years all remains connected with the Second World War have been documented by these means. Aerial archaeology is thus entering areas formerly reserved for other disciplines (history of architecture, military history etc.). Aerial photographs are an excellent tool for documenting the so-called ?cultural landscape?. In a rapidly-changing world it is important to document the most valuable monuments in their spatial and cultural contexts. Aerial photographs allow decisions to be taken concerning the protection not only of individual sites, but also whole complexes of monuments.

The importance of aerial photography is indicated by the size of their collections: in Great Britain over 5 million vertical and 800 000 oblique photographs are catalogued. These are held at a number of centres in the country.