EHG5322 - Watching Brief - Achlachan Windfarm Electric Line, Mybster, Caithness

A programme of archaeological watching brief was undertaken in order to monitor the excavation of the cable trench for a high voltage 33kV cable extending between an electricity substation (under construction) on the Achlachan Windfarm site in Caithness and the existing Mybster Substation sited some 2.5km to the east alongside the A9 carriageway. This cable would enable new turbines constructed at the windfarm to be connected with the National Grid. The cable trench extended for c 2.1km over moorland, improved and managed grassland, and roadside verge, following an asymmetric z-shaped route between the windfarm site and the A9. A preliminary desk-based assessment of the route and its environs identified several prehistoric monuments in the vicinity including the nearby Ballone Broch located just north of Mybster Farm. The recorded heritage assets indicated that the development corridor lies within an extensively occupied prehistoric landscape, buried remains of which could be present along the cable trench route. Furthermore, the area around the adjacent settlement of Spittal was historically an important regional focus for several centuries, in which the former inns at Mybster and at Achkeepster to the south played their part. Monitoring of excavations for the cable trench failed to identify any important buried archaeological deposits or structures. Minor features recorded were restricted to a palaeochannel containing peat deposits and an associated humified buried soil, which were located towards the southwest end of the cable trench. Whilst these naturally occurring features could provide information concerning the history of the natural environment, climate and landuse, no related archaeological deposits or artefacts were identified. Archaeological activity was restricted to the modern period and evidenced by the cutting of two large rubble-filled pits and by the laying of two field drains. In view of these largely negative results, no further analysis and reporting work is recommended. <1>