The shoreline itself was hundreds of metres north of its present location.[4] The raised area in the north-west corner, called the "Eye", has been farmed since the earliest human habitation. It was 28 ha (70 acres) in extent in 1651, but is now much reduced by coastal erosion.[5][6] Access to the Eye was by an ancient causeway, passable at low tide.[6] John Heydon started the process of embanking the marshes to reclaim the land in 1522, and his banks were extended and improved by Dutchman Jan van Hasedunch from 1630.