Remains of post-medieval warping drains to the north-west of Blyton, identified as cropmarks and earthworks on aerial photography. Despite considerable erosion and infilling, the drains can be seen clearly as broad channels flanked on either side by spread banks, c.24m wide overall and with a height (from the bottom of the ditch to the top of the banks) varying from c.1m to more than 2m. Where the drain survives as a cropmark, it shows as four parallel parch marks, turning at a sharp angle and linking up with the earthwork section. {1}{2}{3}