English: cropped version of Commons file Holkham_Iron_Age_Fort_from_the_Joe_Jordon_Bird_Hide_-_geograph.org.uk_-_443400.jpg The iron age fort is viewed here from the Joe Jordon hide which is in a raised position overlooking both the fort and an area of water shown to the right, part of Holkham National Nature Reserve. An English Nature information board inside the hide states that "The raised area of humps and bumps you can see from the windows of the hide are the remains of an Iron Age (650 BC to AD 43) fort, known as Holkham Camp. It is one of only six sites of this type known in Norfolk." It also states that "The site was chosen because it was easy to defend at the time, being at the end of a sand spit that was isolated from the mainland by tidal salt marshes. The only access by dry land to the fort was from the seaward side, along the narrow raised sand spit that can be seen running from beneath the hide to the fort."