Photo Charles Taylor

Work started on the largest motte in England in 1067 and in c.1125 the great 70 foot high stone keep was added. During the 14th century it was used as a prison and allowed to decay until it was refortified during the Civil War. The keep was refaced in the 19th century. It is now used as a museum of fine art, archaeology, and natural history.

On the bank of the river nearby is Cow Tower, once a toll house but converted in 1398 into an artillery tower which became one of a number of towers used as part of the Norwich defences. It stands 50 feet high and unusually is faced with bricks.

The city was protected by a wall which was constructed between 1337 and 1344, part of which still stands.