Geophysical survey at The Wirk reveals buried walls of the hall

Project leads, Drs Sarah Jane Gibbon and Dan Lee reveal the results of the geophysical survey part of their project on The Wirk funded by the Castle Studies Trust.

Thanks to a grant from the Castle Studies Trust, ateam from the Orkney Research Centre for Archaeology undertook geophysical survey at The Wirk, Westside, on the island of Rousay, Orkney in September, despite the challenges. Long grass was cleared from the site and a grid was established to the north, east and west of the stone-built tower. Two techniques were used: magnetometer survey (good for identifying magnetically enhanced material from burning and settlement activity) and earth resistance (good for locating walls and structures).

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The aim is to better understand the nature and date of the tower which has variously been interpreted as a 12th century Norse Castle, a hall-house tower, a defensive church tower and a 16th century tower and range. Previous excavations by J. Storer Clouston in the 1920s cleared the stone tower and exposed a large range to the east, although phasing of the buildings remains unclear. The tower was left exposed but the area to the east was backfilled. A scale plan was made but recording and description of the built remains was minimal.

High-resolution magnetometer survey and targeted high-resolution earth resistance survey was undertaken across the site in order to characterise the buried structures, put the tower and hall in context and inform trench location. Clear anomalies were identified in both surveys at the site of the hall, with potential wall lines (high resistance) matching the main part of the building in Clouston’s plan to the east of the tower. This suggests that wall footings are likely to survive just below the ground surface. Other high resistance anomalies to the south of the hall could indicate the presence of additional structures. Results from the magnetometer survey showed strong positive and negative anomalies within the footprint of the hall and confirmed the presence of a possible enclosure to the south. A curvilinear positive anomaly to the north-west of the tower, beyond the apron, could indicate the presence of another small enclosure.

Overall, the geophysical survey has demonstrated that the footings of the hall survive to the east of the tower, accompanied by newly discovered enclosures with possible structural elements to the south and north-west. The extent of the site appears to extend beyond the visible remains with anomalies continuing into the kirkyard.

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Featured image copyright of Bobby Friel @TakeTheHighView

ORCA have had to postpone the evaluation excavation until next year, but the prospects are looking good to expose some of the hall.

Is the The Wirk a Castle? Archaeological investigations in Rousay, Orkney

With HES giving the provisional sign off for the excavation at The Wirk to take place in the week commencing 21 September, and the geophys survey to take place the previous week, project leads Drs Dan Lee and Sarah Jane Gibbon outline the background to the project and what they hope to find.

Located on the south-western coast of Rousay, The Wirk is located in one of the most archaeologically rich parts of Orkney. The Orkney Research Centre for Archaeology (ORCA) is undertaking geophysical survey, archaeological excavations and 3D modelling at this enigmatic castle site (pending approval from HES).

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The Wirk, meaning stronghold in Old Norse, and with the alternative name Westness Castle, is a small stone tower located close to the coast. It has variously been interpreted as a 12th century Norse Castle, a detached fortified bell-tower, a 13th century defensive tower for an incomplete church, a hall-house garderobe tower and most recently a 16th century tower and attached range.

The Wirk located on the side of  St Mary’s Church graveyard, looking south. credit: Bobby Friel @TakeTheHighView

Minor clearance and excavation in the 1920s identified similarities in construction between The Wirk and the 12th century Cubbie Roo’s Castle, on the nearby island of Wyre, considered to be one of the earliest stone keeps in Scotland. The Wirk is located in Westness which has been a large estate since at least the 12th century when it was the home of the Norse chieftain Sigurd of Westness (Orkneyinga saga). It is adjacent to Rousay parish church, likely to date from the 12th century, with standing remains of 16th century date on earlier footings.

Recently, the 12th/13th century date attribution of The Wirk has been rejected in favour of a 16th century date. This new interpretation is based on the built remains and 16th century architectural fragments which were found in the 1920s. However, architectural fragments of 12th/13th century date were also present and nearby archaeology, particularly the discovery earlier this year of a Norse hall at Skaill by the UHI Archaeology Institute would suggest this was a high-status place in the saga period. This is not to dispute that The Wirk may also have been in use in the 16th century when the estate was owned by a prominent Orkney family. One of the objectives of this project is to excavate trial trenches over Clouston’s excavation and at the eastern end of the site to identify the earliest phases of the tower and adjacent building. Upper parts of the tower were substantially rebuilt in the 19th century and so excavation will allow us to record parts of the site that have not been knowingly rebuilt.

Inside The Wirk tower, looking southeast, showing the entrance to an underground well or passage (Image: Dan Lee)

Along with the excavations, targeted geophysical survey around The Wirk aims to better understand any relationships between the tower and the buildings/features which surround it. 3D modelling of The Wirk and Cubbie Roo’s Castle will enhance our understanding of these comparable sites and allow the public to explore the remains online.

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References and further reading:

Clouston, JS 1931 Early Norse Castles. The Orcadian. Kirkwall

Gibbon SJ 2017 A Survey of Norse Castles in Orkney, in P Martin (ed) Castles and Galleys: A reassessment of the historic galley-castles of the Norse-Gaelic seaways. Islands Book Trust. Laxay. 226-248.

HES 2017. Skaill farm survey, The Wirk http://canmore.org.uk/event/1040199

HES 2020. The Wirk http://canmore.org.uk/site/2282

HES 2020. Skaill farm, Rousay http://canmore.org.uk/site/351514

Tabraham, C 1997 Scotland’s Castles. BT Batsford. London.

UHI 2019: https://archaeologyorkney.com/2019/08/06/norse-hall-discovered-at-skaill-rousay-orkney/

Featured image: View of The Wirk, located on the righthand corner of St Mary’s Church yard in the foreground, looking northwest to Midhowe and the Atlantic Ocean (Image: Bobby Friel @TakeTheHighView).