In 2002, a geophysical survey — part of the Orkney World Heritage Site Geophysics Programme — revealed a huge complex of anomalies, “indicative of settlement”, covering an area of 2.5 hectares on the south-eastern end of the Ness.
The sheer concentration of anomalies, and the variation, astonished the archaeologists.
As it was thought the stone was part of a Bronze Age burial cist, and therefore there was the possibility that human remains had been disturbed, a rescue excavation was undertaken by Beverley Ballin-Smith and Gert Petersen, from the Glasgow University Research Division.
The discovery led to a resistivity survey to try to define the extent of the built archaeology and complement the initial gradiometer survey.
The results of these two surveys confirmed that something large and complex lay under the soil, so further investigations began.
In 2004, eight test-trenches were placed across the site to examine the nature, depth and extent of the suspected archaeological deposits.
They confirmed that much of the mounded ridge is artificial, comprising structures and middens, all dating from the Neolithic.