 It may have been built around the same time as Iron Age blockhouse forts in Scotland such as the Crosskirk Fort in Caithness and the Clickimin Fort, Ness of Burgi Fort and Huxter Fort in Shetland.A sample of wood found in a ditch lying partly under the stone wall was dated to around 580 BC, so the wall is no older than that.Another piece of wood in a deposit overlaying the base of a retaining wall was dated to around 800 AD, indicating that the wall was built before that date.