A finely preserved Iceni ditch and banked enclosure on the salt marshes near Holkham. Access is poor as the area is a nature reserve, but a good view can be had from the high observation hide overlooking the marshes on the edge of the woods. The camp was also reputedly used by the Danes.
While visiting, also take the time to visit the wonderful expansive beach on the other side of the woods.
Originally Iron Age? used by the Romans and maybe the Vikings later. It's right on the saltmarsh at Holkham, and used to be accessible by a creek, so is protected by the sea as well as a single rampart.