Hi Min,
Did all that area pre dog,loved it.Ended up in Yorkshire so We could combine with a familt visit.Hoping to do the Broads area in the near future.The warning about Sandringham came up on a current search and I had forgotten all about it until a friends dog caught it in Yorkshire.We have the dreaded Portugese Man of War jelly fish down here, couple of dogs have been stung , the tentacles stay live even if the thing looks dead, been advised to carry Piriton just in case.At leadt you can see them on the beach.