Dunoon Castle is a ruined 12th century castle located at Dunoon on the Cowal Peninsula in Argyll and Bute, Scotland. The castle sat upon a cone-shaped hill about 80 feet high. The castle was a royal residence in the 14th century, and in the 17th century fell into ruins. The castle originally belonged to the Lamont family but became a royal castle with the Earls of Argyll (Campbells) as hereditary keepers, paying a nominal rent of a single red rose to the sovereign. In earlier times, Mary, Queen of Scots stayed at the castle circa 1563 and granted several charters during her visit. The castle was destroyed during the rebellion in 1685.