The monument includes a motte and bailey castle situated on a gentle north- facing slope on the northern edge of the North Downs, lying within the boundary of a disused military airfield. The castle survives as earthwork remains which include a substantial earthen mound, or motte, surrounded by a large moat. To the south east are the remains of a formerly walled bailey within which lie the upstanding remains of a tower, thought to represent a mural tower. The motte survives as an oval earthwork mound which stands to a height of c.5m above the surrounding ground level. The mound has a flat top which measures c.40m north east/south west by c.28m across. Built into the mound are World War II air raid shelters. These have brick entrances in the side of the mound; the main chamber is constructed from steel and concrete situated at approximately ground level, with a brick ventilation shaft. Surrounding the motte is a moat which, although partially infilled, is still visible to a depth of c.4m and up to c.18m wide to the north, west and south. To the east of the motte the moat has been deliberately infilled and now survives as a buried feature. Lying beyond the infilled moat on the south east side of the motte is the castle bailey. This area was originally enclosed by a wall but the only upstanding masonry remains which now survive are the ruins of a possible mural tower which was incorporated into a later medieval manor house which is a Grade II Listed Building. This is included in the scheduling. The wall survives to a height of c.7.5m at this point and is built of flint and ragstone. Elsewhere the line of the bailey wall is visible as a terrace which runs south from the tower with a drop of c.1m to the east. There is a second slight terrace further west, with a drop of 0.5m on the east side, possibly indicating the line of an internal division within the bailey. Situated on the outer bank of the moat in the north west corner of the monument is a concrete bunker also dating to World War II. Excluded from the scheduling are the warehouse, fences and fence posts, although the ground beneath all these features is included. MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation. Reasons for Designation Motte and bailey castles are medieval fortifications introduced into Britain by the Normans. They comprised a large conical mound of earth or rubble, the motte, surmounted by a palisade and a stone or timber tower. In a majority of examples an embanked enclosure containing additional buildings, the bailey, adjoined the motte. Motte castles and motte-and-bailey castles acted as garrison forts during offensive military operations, as strongholds, and, in many cases, as aristocratic residences and as centres of local or royal administration. Built in towns, villages and open countryside, motte and bailey castles generally occupied strategic positions dominating their immediate locality and, as a result, are the most visually impressive monuments of the early post-Conquest period surviving in the modern landscape. Over 600 motte castles or motte-and-bailey castles are recorded nationally, with examples known from most regions. As one of a restricted range of recognised early post-Conquest monuments, they are particularly important for the study of Norman Britain and the development of the feudal system. Although many were occupied for only a short period of time, motte castles continued to be built and occupied from the 11th to the 13th centuries, after which they were superseded by other types of castle. Despite disturbance caused by the wartime military use of the site, Binbury motte and bailey castle survives comparatively well. The summit of the motte and the area of the bailey have remained largely undisturbed and contain archaeological remains and environmental evidence relating to the monument and the landscape in which it was located. Walled baileys are unusual in motte and bailey castles, although this is one of two examples to survive within 2km, the other being Thurnham Castle. Archaeological and documentary evidence from both these sites will give an insight into the construction of this particular form of bailey and its use, as well as the economy and way of life of the inhabitants of the sites.