了望孔 meaning in Chinese

loophole

Do you think the eyes of the white tower are blind
你以为白塔的了望孔仅仅是摆设吗
The house consists of three rows of houses arranged to form a rectangle . all the houses are interlinked by passages and small courtyards . embrasures and loopholes were arranged orderly on the fortified walls and defensive towers were built at the four corners to ward off enemies
曾大屋呈长方形，共三进。屋与屋之间有通道及天井相连；围墙上有排列整齐之枪孔及了望孔，围墙的四角有更楼和炮楼，用以防御外敌入侵。