The remains of a manorial work now covered in dense undergrowth. The outer ditch turns away on the south and becomes very shallow, and difficult to trace. An inner rampart, some 2ft 6ins at its best, encloses a level space with perhaps traces of a wall in the north-east corner. There is a slight outer bank and ditch, totally wanting on west. Both ramparts have entrances. At the south-eastern extremity is small enclosure not marked on map. No relics found. Probably moated manor site. Castle Dyke scheduled under 'Other secular sites and buildings'. {1}{2}{3}{4} A double enclosure on a thickly wooded level site. The inner enclosure is approximately rectangular with rounded angles, ditch 8 yards wide, 4ft deep, and slight inner bank. Stands approximately in centre of outer enclosure, also rectangular, with ditch less well marked:- 7 yards wide x 2ft deep, almost invisible on west side. Slight inner bank. Possible medieval castle site - compare Woodhead Castle, Great Casterton, for a much better example of a similar type of enclosure. {5}{6} Aunby originally formed part of the manor of Bytham, passing, along with other parts of the manor, to the earls of Albemarle shortly after the Conquest. The manor of Bytham passed to the de Colville family, thought to have been resident in Aunby in the 12th century. Aunby is thought to have been established during a period of population growth in the late 12th/early 13th centuries: a documentary reference to assarting at Aunby dates to the early 13th century. The monument itself is a moated island enclosed by an embanked ditch, creating an outer enclosure. A small sub-rectangular enclosure extends from the south-western corner. The moated site and surrounding enclosures, covering an area measuring c.170m by 95m, are thought to represent a manorial complex of medieval origin. The island would have contained buildings such as the manor house and domestic or ancillary buildings: remains of these are thought to survive below ground level. A causeway crosses the southern arm of the ditch to the island, and the outer enclosure would have been occupied by ancillary buildings or provided accomodation for stock. The smaller enclosure would have formed a paddock for stock. All fence posts and hides are excluded from the scheduling, although the ground beneath them is included. A 2m boundary around the archaeological features is included, considered essential for the support and preservation of the monument. {7}