Not sure about in Norwich much but just outside of Norwich there is the Dinosaur Park which is a great place to visit with or without a family. It has models of most of the dinosaurs with information boards for each. There is also a petting area with Pigs, Chickens and Wallaby's to name a few. If you take children and need a rest then let them on the outdoor play area or if a wet day there is a large indoor play area (although I think there may by an additional cost for this). All in all a great fun day.