Hopton Castle was an 11th century earthwork motte and bailey fortress, founded by Robert 'Picot' de Say. In 1276, Walter de Hopton founded the stone castle and added an impressive rectangular two storey keep, with a projecting stair turret to the low motte. The keep with its 16th century attic displays the rare features of, double string coursing around the two western turrets, fragments of plaster rendering on its outside walls and a 'guard shoot' at ground level in the south-west turret. The inner bailey, is lined with the foundations of ranges of buildings, encased by a curtain wall and flanking towers. This low lying castle was defended by a large 14th century outer bailey platform, marshy ground and wet ditches. Half a mile south-east is Hopton Motte.