3 days out for the price of 2! Banham Zoo, Africa Alive and Dinosaur Adventure http://www.thebig-3.com/where-is-big-3.asp Caister Castle and Car Museum/collection http://www.greateryarmouth.co.uk/caister_castle.htm
If you would like to discover parts of Norfolk you wouldn't otherwise see and have great fun doing so, try a family trip out with 'The CanoeMan' - my husbad did this through his firm and highly recommends it http://www.thecanoeman.com/ A sports and leisure site with lots of info on trekking & cycling worldwide http://www.adventure-trek.co.uk/