emains of a motte and bailey castle later altered to have a shell-keep. The shallow circular keep is built upon a mound some distance from the River Dart. The keep is not perfectly round but has a diameter of around 66 feet one way and 71 feet the other. The walls are around 12 feet high. There are no remains of the buildings within the shell-keep above ground. To the north-west of the keep and mound is the bailey, which is roughly circular and surrounded by a moat. The original motte and bailey castle is believed to have been built shortly after the Norman Conquest by one of William the Conqueror's supporters. Two more shell-keep castles can be found in Cornwall, these being Restormel Castle and Plympton Castle.