Situated on a gravel bank just 2 metres (6 ft 7 in) above sea-level, it is the lowest hill fort in Britain.
Around 500 BC, when fortification is thought to have begun at this site, this "hill" would have provided a significant area of habitable land amidst the flooded marshes of the fens.
[1] The fort is a possible site of the battle of 47 AD mentioned by Tacitus, between the Iceni tribe and a Roman auxiliary force under governor Ostorius Scapula.
Human remains have been found around the site including sword-marked adult bones and the cleaved skull of a child, indicating that the inhabitants were trapped and attacked within the settlement.
To prevent further damage by agriculture, the area is now designated as a pocket park[2] and scheduled ancient monument.