在紫禁城城墙上的四角,各建有一座造型奇特、风姿绰约的角楼。角楼平面呈曲尺形,结构为九梁十八柱,屋顶有七十二条脊,正中安铜鎏金宝顶,形象生动灵秀,巧夺天工。城墙建角楼之举古已有之,主要用于防卫望,但像紫禁城角楼这样的神品,却是绝无仅有之作,它的优美造型为紫禁城平添了无限神韵(整组建筑由约1500件构件拼接搭建而成,并可拆分组装为独立的重檐摩尼殿和三重檐藏经阁)。
In each of the four corners of the walls of the Imperial City stood a corner tower, shaped like + when viewed from above. The roofs of these tower were double-eaved and hipped and gabled in a complex 72-ridge style. The exterior of the corner tower are not terribly rigid in adhering to the formal restrictions for palace hall. (consist of about 1500 component pieces )