The octagonal plan is unusual in castle design.

Kidwelly is an outstanding example of late 13th-century castle design, with its 'walls within walls' defensive system.

Z Plan is a form of castle design common in England and Scotland.

These French engineers disappeared from the scene before the castle design appeared in the American Army.

Todo Takatora is also famous for excellence in castle design.

At the time of the stone castle's creation, Kidwelly benefited from the latest strategic military thinking in castle design.

The castle design formed an inner and an outer ward, surrounded in turn by a moat, now partially filled.

The architect applied the latest in castle design: the passages leading to these gates were full of twists and turns.

Although motte-and-bailey castles are the best known castle design, they were not always the most numerous in any given area.

Newer castle designs, however, placed less emphasis on mottes.