An Iron Age enigma

An enigmatic type of Iron Age structure found in Orkney goes by the uninspiring title of "earth-house".

Orkney's earth-houses - generally known as souterrains elsewhere in Britain - usually comprise of a long, underground entrance passage leading to a round chamber.

Some British souterrains are visible above ground, but the Orcadian versions are completely subterranean. Sometimes, as in the case of the Grain earth-house, the chambers were built quite deep underground.

These chambers, of which two fine Orcadian examples remain, date from sometime in the first millennium BC. Why they were built, and what they were used for, however, is not clear. The discovery of the remains of 18 people in the Rennibister earth house in Firth really muddied the waters in this respect.

There has been little excavation work concentrating on Orkney’s earth houses in modern times, but their association with domestic structures, i.e. houses, has led to the assumption they too had a purely domestic function - usually storage.

But there are problems with this interpretation.

Firstly, there is a distinct lack of evidence to show what, if anything, was ever stored in the chambers. Secondly, as any modern visitor will attest, there are obvious difficulties involved in accessing the underground chamber.

Because of this, some now believe the structures had a more ritualistic, or religious, purpose.

It is thought that the earth house entrances were found within the dwelling houses above ground, a feature reminiscent of the underground "wells" found in Iron Age brochs. This may add weight to the theory that earth houses were more than mere storage areas.

In this respect it is interesting to note that at least two earth-houses - at Howe in Stromness and Rowiegar on Rousay - were constructed within out-of-use Neolithic chambered cairns.