Also written 扇子の縄. A castle plan shaped like a folding
fan wherein the fortifications are distributed on either side of the castle water
supply. In the case of mountain castles where the water supply was typically located
below the mountain top in a valley lake, a fortification would be built there
to guard the water source. The main compound located at the mountaintop would
be sited where the pivot of the folding fan would be. A wall or embankment was
built along the curve of the fan to protect the water source. |