The fortification was a square enclosure , approximately 350 meters east - west by 370 meters north - south , consisting of a 2.4 meter thick earthen rampart surmounted by a wooden palisade .
The fortification protected by a 3 - 4 meter wide dry moat .
The fortification was a square enclosure , approximately 350 meters east - west by 370 meters north - south , consisting of a 2.4 meter thick earthen rampart surmounted by a wooden palisade , and protected by a 3 - 4 meter wide dry moat .