At the end of the Sengoku period (period of warring states), when modern fortresses started to be built, yaguras were built on the foundation stones, with tiled roofs and thick clayey walls to prevent fire and bullets.
戦国時代(日本)末期、近世城郭が築かれ始めると、櫓は礎石の上に建ち、防火と防弾を考慮して厚い土壁が塗られ、屋根は瓦で葺かれる。