Positioned on the main route between Norway and the Western Isles, Thurso Castle was originally a Viking stronghold. It was later acquired by the powerful Sinclair family and in 1660 the castle was substantially rebuilt. In the late nineteenth century the entire structure was transformed into a Gothic style mansion and these are the ruins that survive today.



The first fortification at Thurso was raised by the Norwegians probably in the form of an earth and timber structure but little is known about it other than a record dated 1157 which confirmed its existence. The Norwegians dominated the north and west coasts of Scotland until the mid-thirteenth century and Thurso, which was centrally located on the route from Norway to the Western isles, was chosen as a key residence to serve the Earls of Orkney and Caithness. The name Thurso originates from an Old Norse phrase which translates as 'Thor's River'.


By the seventeenth century vast swathes of Caithness and Sutherland were under the control of the powerful Sinclair family. Around 1660 George Sinclair, Sixth Earl of Caithness started work on a new castle to replace the former facility. Work was overseen by Donald Ross and thereafter the site became George's primary residence. He was an important magnate in northern Scotland but found himself embroiled in a bitter land dispute with the equally powerful Campbells of Glenorchy. Attempts to resolve the issue through the courts were followed by a decision by the King in favour of the Campbells. This prompted George Sinclair to mount a protracted guerrilla campaign against his rivals. Thurso Castle, along with other Sinclair properties at Keiss and Girnigoe, were seized by the Campbells but then attacked and badly damaged by George's men. The dispute was eventually resolved following intervention by James, Duke of York (later James VII and II) and thereafter Thurso was repaired. The structure was upgraded on several occasions in the early nineteenth century.


The castle was substantially rebuilt in 1872 by Sir Tollemache Sinclair. The new structure was designed by David Smith and took the form of a Scottish Baronial Gothic mansion. Large swathes of the seventeenth century castle were either demolished or incorporated into the new structure. The build quality of the new mansion was poor however and in 1952 much of the structure was demolished for safety reasons leaving just the sections visible today.




Brown, K.M (2000). Noble Society in Scotland: Wealth, Family and Culture from Reformation to Revolution. Edinburgh University Press, Edinburgh.

CANMORE (2016). Thurso Castle. Royal Commission on the Ancient and Historical Monuments of Scotland.

Coventry, M (2008). Castles of the Clans: the Strongholds and Seats of 750 Scottish Families and Clans. RCAHMS, Musselburgh.

Falkus, M and Gillingham, J (1981). Historical Atlas of Great Britain. Grisewood and Dempsey, London.

Lindsay, M (1986). The Castles of Scotland. Constable, Edinburgh.

Simpson, W.D (1959). Scottish Castles - An introduction to the Castles of Scotland. HM Stationery Office, Edinburgh.


What's There?

Thurso Castle can be viewed from a public footpath but there is no access to the structure itself. The ruins visible are all from the re-styling of the structure in 1872.

Getting There

Thurso Castle is found in Thurso East off Sir Archibald Road. The best views of the castle are from the other side of the River near car parking option shown below. Visitors can then take a short walk to the ruins.

Car Parking / Viewpoint

KW14 8BN

58.597461N 3.514188W

Thurso Castle

No Postcode

58.599271N 3.508332W