Knock is a small but attractive tower, strategically built on top of a hill where Glen Muick meets the Dee valley just west of Ballater. It is up a long rough track signed to Knock Farm and is cared for by Historic Scotland. It is an oblong keep of four storeys with no wings, and once had a vaulted basement, now collapsed. Both the east and south facing corners have circular angle turrets supported on fine label corbelling, and the west facing corner has a square watch chamber corbelled out above the stairhead. This was a Gordon house, and like so many another, saw its share of tragedy. Henry Gordon, second of Knock, was killed in a raid by a company of Forbes and Clan Chattan. He was succeeded by his brother Alexander, who is said to have built the castle as it now stands, at the beginning of the 17th century. According to tradition, the Forbes surprised, attacked and slew all seven of his sons as they were digging peats nearby. Their severed heads were left attached to their peat cutting spades. On hearing this dire news, the laird was so overcome that he fell down the stairway at Knock and broke his neck. Forbes of Strathgirnock was summarily condemned and executed for leading the affray, by Gordon of Abergeldie as deputy for the Gordon Earl of Huntly, and his lands annexed to Abergeldie – a proceeding that can hardly be considered impartial, however warranted, but which was sadly typical of the time.