
Corner towers arefortified towers built at the corners ofcastles orfortresses.
Two ideas have been advanced about the purpose or value of corner towers in medieval fortresses:
Towers constructed at fortress corners were larger and taller than other towers. At the bottom of these towers were defences, such asditches, fences, and sometimes advanced forts orbastions.[2]
Corner towers may be seen on theWall of Philip II Augustus (Tour du coin (Louvre),Tour de Nesle,Tour Barbeau [fr]), on theWall of Charles V (Tour du Bois [fr]), in the city ofCarcassonne, in theChâteau de Pierrefonds and in the fortress of theBastille.
In architecture of non-defensive structures, like churches and theater buildings, a corner tower is any tower that is protruding upwards from the corner of two walls, and usually has no walls of its own below the roof. While other towers are usually attached to the building by one wall.