Originally a three-storey building named “Hall of Watching the Moon Toad” which was completed in Emperor Qianlong’s reign (1736-1795), the hall was rebuilt with just one floor during the reign of Emperor Jiaqing. It became a wonderful place for emperors and empresses to enjoy the moonlight during summer and autumn evenings. Emperor Qianlong used to sit here to watch displays performed by the naval regiment, the Tough and Sharp Troops of the Fragrant Hills. Burned down by the Anglo-French Allied Forces in 1860, the hall was rebuilt during Emperor Guangxu’s reign (1875-1908). The Empress Dowager also used to sit here to enjoy displays given by the naval academy.