hira-ishi 平石

Also tsuki-ishi 築石. Broad, flat construction stones used to build the main sections of stone walls *ishigaki 石垣, excluding corners. Often used in castle walls. Hira-ishi are typically about 2 m in depth, 90 cm high, and 90 cm wide. The visible face of the stone is called ishizura 石面, the depth *ishi-no-hikae 石の控え, and the end ishijiri 石尻. Stones used for corners are called *sumi-ishi 隅石, *sumijiri-ishi 隅尻石, or sumiwaki-ishi 隅脇石.