The Cow Tower is an artillery tower by the River Wensum in Norwich, Norfolk, England. Built between 1398 and 1399 by the city authorities in response to the threat from France and indigenous English rebels, the tower was intended to defend the north-eastern approach to Norwich with hand cannons and bombards. It stood apart from the main city walls, close to the river where its height would have allowed it to fire onto the higher ground opposite the city. The tower was designed to hold a garrison when required and was well furnished, probably using different floors for dining and sleeping.