Not all early castles were of earthwork and timber only; some belong to the category of motte-and-bailey. The main enclosure was the bailey, defended by a ditch, bank and palisade, with a timber gate or gate tower; the bailey contained all the residential buildings, presumably timber-framed, required by a lordly household, at least in the first generation. To this was added the motte, usually to one side with direct access to the open country, the whole looking like a figure of eight, with the area of the bailey larger than that of the motte. The motte itself was a great mound of earth, usually artificial, though sometime part-natural, with its own ditch and bank about the base and thus separated from the bailey, from which it summit was reached usually by an inclined and stepped timber bridge. In the classic model a timber palisade with a gateway crowned the flattened summit of the mound and within this there rose a timber tower.