Cantley marshes,Buckenham,hickling,horsey,in fact theres loads of places,the north coast is my favourite,too many to mention,well,i will give you a few.Titchwell,holme,blackeney,brancaster,cley,seahouses just for starters.
I went in my caravanette a few years ago,just drove up and drove around,birding etc,didn't really have an itineray,kipped wherever i could and had a great time.