Běi / jīng / de / gǔ / chéng lóu / shì / míng / qīng / liǎng / dài / zhòng / yào / de / jūn / shì / fáng / yù / jiàn / zhù

北京的古城楼是明清两代重要的军事防御建筑。

The ancient city gate towers in Beijing are important military defense buildings of the Ming and Qing dynasties.