Norwich was, according to Susan Foreman, a city in Norfolk, England. After being miniaturised, she and Ian Chesterton discovered a picture of night scented stock from the Ralph Seed Co. Ltd, of Norwich. (TV: Planet of Giants)
In 2007, Norwich was "invaded" by the Zaross, a fictional species who were actually Herazi in disguise. Jackie Tyler was visiting the city at the time and informed Rose Tyler and the Tenth Doctor of the event. Once the Zaross had left Norwich, Torchwood personnel arrived to "clean up" what was left behind. (AUDIO: Infamy of the Zaross)