The subterranean structure came to light while farrowing a field near Corrigall. The farmer noticed two holes had appeared in the ground, with the soil dropping down into what appeared to be a rocky pit.
The discovery is causing some excitement as it is one of the only Orcadian earth-houses found in recent times that has not been disturbed – either by later activity on the site or by more-recent antiquarian studies.
Orkney’s earth-houses – generally known as souterrains elsewhere in Britain – usually comprise of a long, underground entrance passage leading to a round chamber.
Their association with what were thought to be overhead houses led to the long-held assumption that they had a purely domestic function – usually storage.
A team of archaeologists, led by Judith Robertson, is now working on the Corrigall earth-house, working down from the top of the chamber.
The chamber is roughly oval shaped, measures around two metres by three metres and is probably about a metre deep. At the early stages of excavation, it appears that a passage runs off from the south east of the chamber, with another feature in the south west that could be a second passageway.
Pottery sherds found on site would indicate that the chamber is early Iron Age, dating from around 700-500BC.
At the time of writing the layout of the interior is unclear, as the chamber was filled with collapsed earth and rubble, however it appears that the stone roof was supported by at least four large stone pillars.
To the north is what appears to be a paved area, with a definite stone socket hole, flanked by a circular rock cut pit that was found to contain ash and charcoal. It is hoped these cremation deposits can be radio-carbon dated to provide a date for the souterrain.
The Iron Age builders cut into solid bedrock in a natural rise in the landscape to allow the construction of their earth-house, reusing the stone from their quarrying operation to cover the flagstone roof.
The presence of two larges “notched” stones, similar to the one uncovered on the Ness of Brodgar in 2003, once again hints that the Iron Age builders were incorporating fragments of earlier structures into their own. The stones, which are thought to be notched to allow them to be lifted, would not have been accessible once the earth-house had been covered over – so the notches must have had an earlier purpose.
Although there is no evidence yet of an associated above ground structure, geophysics scans of the area hint that the chamber might have been situated on the outskirts of a large settlement area.
It is hoped that the Harray structure will add to the ongoing work on souterrains by Martin Carruthers, an archaeology lecturer at Orkney College, to provide a clearer picture of the structures’ role in Orcadian prehistory.
Martin is studying Orkney’s subterranean structures for his PHD and, after three years work on the Windwick earth-house in South Ronaldsay, suggests the chambers had as much to do with ritual, and in particular the dead, than a place to stash crops.
The three-week excavation is being funded by Historic Scotland.