From Li Bai's (
李白) Tang poem 《
登庐山五老峰》 (Climbing the Five Old Men Peaks of Lushan):
庐山东南五老峰,
青天削出金芙蓉。
九江秀色可揽结,
吾将此地巢云松。Another related Li Bai line on Lushan declares the cataract '
壮观天下无'. The phrase became a set expression for scenery of breathtaking, unrivaled magnificence.