Noltland Castle dates mainly to the later 16th century, although it was never fully completed. In 1560 Adam Bothwell, Bishop of Orkney, granted the lands of Noltland to his brother-in-law Gilbert Balfour, who built the castle. Balfour was Master of the Royal Household to Mary, Queen of Scots, and was involved in the plot to kill her husband, Henry Stuart, Lord Darnley. After Mary's deposition and exile, he continued to support the queen. Noltland was seized by Robert Stewart, 1st Earl of Orkney, an opponent of Mary's supporters, but he was forced to hand it back to Balfour in the early 1570s. Balfour died in Sweden in 1567, and in 1598 the castle was again seized by the Earl of Orkney (now Patrick Stewart, son of Robert). By 1606 the castle had been restored to the Balfours once more, when it was sold to Sir John Arnot, Lord Provost of Edinburgh, who later became Sheriff of Orkney.
During the Wars of the Three Kingdoms in 1650, Royalist officers occupied the castle after their defeat at the Battle of Carbisdale. Local Covenanters captured and burned the castle. By 1881 it was described as a ruin, and was given into state care by the Balfour family in 1911. it is now maintained by Historic Scotland.
The castle is built in the Z-plan form, comprising a rectangular main block with towers at opposite corners. A courtyard was added to the south in the 17th century. The castle is notable for its defensive architecture, unusual for the period, including a large number of shot holes. The large staircase has been compared to the stair at Fyvie Castle in Aberdeenshire.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.