A little to the north-west of the tower are six rude stones or pillars placed on the summit of an eminence, in a circular order, forming an area of ten yards diameter. The largest is about eight feet high. They are known as the Duddo Stones, and some learned archaeologists have set them down as Druidical; but the local tradition is that they were placed where they stand in commemoration of a victory gained at Grindon, in the year 1558, by the Earl of Northumberland and his brother Sir Henry Percy, over a plundering and burning party of Scottish horse, accompanied, as Ridpath tells us, by some foot, who were either Frenchmen or trained and commanded by French officers, and who were driven in disorder across the Tweed. The accompanying sketch of the stones, showing their appearance in 1836, was published in Richardson’s “Table Book,” vol. iv., 1844.
From ‘North-Country Lore and Legend’ in the Monthly Chronicle for May 1869. Were there six at the time? You can’t see from the drawing (above).