Thurso Castle was never meant to be and never was a stronghold. Plaster sentries are posted on roofs and turrets, guarding the castle from imaginary invaders. The castle has known no violence or dark deeds. It shares the distinction of being the most northerly castle on the British mainland with the exception of the Castle of Mey, owned by the Queen Mother.

In 1872, under Sir Tollemache's guidance, Thurso estate became a monument to Victorian values with the remodelling of the whole structure in the style of the French chateaux at Loire and of Holyroodhouse. Sir Tollemache, who drew up the designs himself, and together with a local mason "stone was placed upon stone in an alarmingly random fashion, so that the completed project defied the laws of physics: stairways led nowhere and the 100 foot tower was built on a foundation suitable for one of 40 feet."