Keywords
Architecture
Castles
Lit. mirror piling. A method of masonry used for a stone wall *ishigaki 石垣. This type of wall uses rocks whose surfaces are fairly large; the spaces between the rocks are typically filed with smaller stones termed *kuri-ishi 栗石 (chestnut stones). Rocks laid vertically are called yang, you 陽 (positive stone), and those laid horizontally are called yin, in 陰 (negative stones); more horizontal rocks are laid at the bottom of the wall, and more vertical ones higher up. The stones are also said to be arranged in groups of five according to the principle of gogyō 五行, a symbolic grouping invented by the garden designer Akisato Ritō 秋里籬島 in the 1820s. This technique is used most for stone walls that are 13 m high.