Aerial Archaeology in Ireland - The Heritage Council

to provide the most useful feedback. These projects often trigger further initiatives, and methodological developments often
help to spawn other projects or the long-term development of interest in an area that can last well over one or two decades.
These include: Rathcrogan (Waddell 1983; Herity 1983, 1987, 1988; Redfern 1998, 2002; and a new Discovery Programme
initiative, 2005); East Limerick (Gowen 1988; Doody 1993a, 1993b, 1993c, 1995, 1996, 2001); Tara (Norman and St Joseph 1969;
Swan 1978; Newman 1997); and ceremonial landscapes in Sligo (Burenhult 1980, Burenhult et al. 1984; Bergh 1995, 2002).
The Discovery Programme has established a corporate policy of integrating aerial archaeology into its research programmes.
As might be expected from earlier initiatives that demonstrated the potential, this has proved highly successful on ceremonial
centres (Newman 1997) and late prehistoric settlement patterns and hillforts (Doody 1993c, 1995, 1996; Grogan 1993, 1996;
Grogan et al. 1995). Further work using aerial photography and digital photogrammetry is now being done to produce 3D survey
models and ortho-photos of monuments and archaeological landscapes. In 2004, the Discovery Programme carried out a 1:1,500
and 1:7,500 aerial survey of Mullaghfarna, Co. Sligo, in conjunction with Stefan Bergh (NUI Galway). In 2005, they carried out a
large 1:7500 aerial survey of North Roscommon, including the area of Rathcroghan and the surrounding landscape.
Aerial archaeology has thus played an important role in developing and elucidating several core research themes of Irish
archaeology — even if in many ways it is still not as universally used in landscape-based archaeology as it might be. It is also
possible to point to a number of other themes where its potential has been clearly demonstrated but not yet fully developed. Three
such themes — early medieval settlement, human exploitation of freshwater and maritime environments, and whole landscape
approaches to long-term social and environmental change — are outlined below. In the first of these, aerial archaeological
aspects have long been established but have not been backed up by relevant fieldwork until recently. In the second, some
particularly important developments in approach have been demonstrated but are only beginning to be formulated into major
research themes. And in the third, aerial archaeology can be seen as providing a key to unlocking the development of more
sophisticated concepts and methods of analysing how the present-day historic environment reflects on long-term social and
environmental change
Early Medieval Settlement Studies
Woodman (1992) was able to show how aerial archaeology had helped to ‘fill the spaces in Irish prehistory’. The fact that
aerial archaeology has not made as notable an impact on early medieval research is perhaps because the interest of aerial
archaeologists like Swan and Barrett at a landscape scale has not yet been taken up by others in research projects to test their
ideas through fieldwork (as noted by Barrett 2002, 6). Yet their observations about distribution, form, pattern and sequence
in early ecclesiastical centres and wider settlement patterns — which might have triggered a series of innovative fieldwork
programmes — are no less valid than the similar issues that sprang from the impact of aerial archaeology on late prehistoric
hillforts and settlements.
For example, there has already been much debate about the distribution and morphology of ringforts and what this means
in relation to interpretations of settlement pattern and social hierarchy (Barrett 1980, 1982a, 1982b, 2002; Stout 1991, 1992,
2001). Stout (2001) has suggested that the relatively small proportion of ringforts identified from existing aerial photographic
coverage (especially CUCAP, OSi and GSI material) in compiling the SMR makes it very unlikely that the distribution indicated
by early Ordnance Survey maps is significantly wrong. It may very well be true that the early OS maps provide a reliable if not
entirely complete indication of the distribution of these very common monuments. But as Barrett has highlighted, limitations in
the timing, scale and clarity of vertical photography, and the coverage, frequency and recurrence of purposive reconnaissance
(especially in tillage areas) are all factors that will have influenced the identification of low earthworks and flattened sites
revealed by cropmarks and soilmarks that both the original OS surveyors and Archaeological Survey of Ireland may not have
seen in their original mapping of monuments. It is also clear from cropmarks that partial clearance of some sites has left them
looking like simple univallate ringforts, enclosures or graveyards, when in fact they once had much more complex morphologies
(Figure 41).
77