Eynsford Castle was originally a Saxon moated site, with a substantial stone building. Standing on a low artificial platform in the flood-plain of the River Darenth, a very early Norman stone enclosure castle, replaced this residence. In 1085, Ralph son of Unspac held the castle for Lanfranc, the archbishop of Canterbury and his son William de Eynsford founded the stone castle. In the late 11th century, the platform was encased by the moat and the lower two-thirds of the existing flint curtain wall. In the early 12th century, the curtain wall was heightened and in the north-east portion of the platform, a first-floor hall and solar block, each over an undercroft was added. The hall and kitchen were re-constructed after a fire in the early 13th century and a forebuilding gave access to the hall. An internal gatehouse of one or more storeys gave protection to the gateway, which was closed by a draw-bar and possibly a portcullis. In 1312, the castle was abandoned after being raided and the buildings dismantled by the descendants of the de Eynsford family. In the 18th century the Hart-Dykes of Lullingstone Castle, used this rare survival as stables and kennels. Little altered by later building works, on Christmas Eve 1872 part of the curtain wall nearest the river, collapsed into the moat. 2 miles north-east at Horton Kirby is Court Lodge.